140 can be written using four 4's:
See also 113
140 has 12
divisors (see below), whose sum is σ = 336
Its totient is φ = 48
The previous prime is 139. The next prime is 149. The reversal of 140 is 41.
140 = 12 + 22 + ... + 72.
140 is nontrivially palindromic in base 13.
It is a harmonic number, since the harmonic mean of its divisors is an integer.
140 is an admirable number.
Together with 195 it forms a betrothed pair.
It is a Harshad number since it is a multiple of its sum of digits (5).
It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.
It is a O'Halloran number.
140 is a nontrivial repdigit in base 13.
It is a plaindrome in base 11, base 13 and base 16.
It is a nialpdrome in base 12, base 13, base 14 and base 15.
It is a zygodrome in base 13.
It is a pernicious number, because its binary representation contains a prime number (3) of ones.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17 + ... + 23.
It is an arithmetic number, because the mean of its divisors is an integer number (28).
140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.
It is an amenable number.
It is a practical number, because each smaller number is the sum of distinct divisors of 140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (168).
140 is an abundant number, since it is smaller than the sum of its proper divisors (196).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
140 is a wasteful number, since it uses less digits than its factorization.
140 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 16 (or 14 counting only the distinct ones).
The product of its (nonzero) digits is 4, while the sum is 5.
The square root of 140 is about 11.8321595662.
The cubic root of 140 is about 5.1924941019.
Adding to 140 its reverse (41), we get a palindrome (181).
Subtracting from 140 its reverse (41), we obtain a palindrome (99).
The spelling of 140 in words is "one hundred forty", and thus it is an aban number and an iban number.