137640 has 64 divisors (see below), whose sum is σ = 437760. Its totient is φ = 34560.

The previous prime is 137639. The next prime is 137653. The reversal of 137640 is 46731.

It is a Cunningham number, because it is equal to 371²-1.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3702 + ... + 3738.

It is an arithmetic number, because the mean of its divisors is an integer number (6840).

137640 is a Friedman number, since it can be written as 310*74*6, using all its digits and the basic arithmetic operations.

2¹³⁷⁶⁴⁰ is an apocalyptic number.

137640 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 137640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (218880).

137640 is an abundant number, since it is smaller than the sum of its proper divisors (300120).

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

137640 is a wasteful number, since it uses less digits than its factorization.

137640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82 (or 78 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 21.

The square root of 137640 is about 370.9986522887. The cubic root of 137640 is about 51.6315173116.

Subtracting from 137640 its reverse (46731), we obtain a palindrome (90909).

It can be divided in two parts, 137 and 640, that added together give a palindrome (777).

The spelling of 137640 in words is "one hundred thirty-seven thousand, six hundred forty".