139840 has 56 divisors (see below), whose sum is σ = 365760. Its totient is φ = 50688.

The previous prime is 139837. The next prime is 139861. The reversal of 139840 is 48931.

It is a nialpdrome in base 8.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6069 + ... + 6091.

2¹³⁹⁸⁴⁰ is an apocalyptic number.

139840 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 139840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (182880).

139840 is an abundant number, since it is smaller than the sum of its proper divisors (225920).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

139840 is a wasteful number, since it uses less digits than its factorization.

139840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59 (or 49 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 139840 is about 373.9518685606. The cubic root of 139840 is about 51.9051525482.

Subtracting from 139840 its reverse (48931), we obtain a palindrome (90909).

It can be divided in two parts, 139 and 840, that added together give a palindrome (979).

The spelling of 139840 in words is "one hundred thirty-nine thousand, eight hundred forty".