656438280 has 64 divisors (see below), whose sum is σ = 1971699840. Its totient is φ = 174838272.

The previous prime is 656438257. The next prime is 656438281. The reversal of 656438280 is 82834656.

It is a super-2 number, since 2×656438280² = 861822430898716800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (656438281) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 113212 + ... + 118868.

It is an arithmetic number, because the mean of its divisors is an integer number (30807810).

Almost surely, 2^656438280 is an apocalyptic number.

656438280 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

656438280 is an abundant number, since it is smaller than the sum of its proper divisors (1315261560).

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

656438280 is a wasteful number, since it uses less digits than its factorization.

656438280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6638 (or 6634 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 42.

The square root of 656438280 is about 25621.0515006703. The cubic root of 656438280 is about 869.0897601063.

It can be divided in two parts, 6564 and 38280, that added together give a palindrome (44844).

The spelling of 656438280 in words is "six hundred fifty-six million, four hundred thirty-eight thousand, two hundred eighty".