656740140 has 72 divisors (see below), whose sum is σ = 2139106032. Its totient is φ = 150111360.

The previous prime is 656740109. The next prime is 656740157. The reversal of 656740140 is 41047656.

It is a super-2 number, since 2×656740140² = 862615222974439200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 108751 + ... + 114630.

It is an arithmetic number, because the mean of its divisors is an integer number (29709806).

Almost surely, 2^656740140 is an apocalyptic number.

656740140 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

656740140 is an abundant number, since it is smaller than the sum of its proper divisors (1482365892).

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

656740140 is a wasteful number, since it uses less digits than its factorization.

656740140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223407 (or 223398 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 33.

The square root of 656740140 is about 25626.9416825340. The cubic root of 656740140 is about 869.2229552804. Note that the first 3 decimals are identical.

Adding to 656740140 its reverse (41047656), we get a palindrome (697787796).

The spelling of 656740140 in words is "six hundred fifty-six million, seven hundred forty thousand, one hundred forty".