656721412 has 24 divisors (see below), whose sum is σ = 1179924480. Its totient is φ = 319674240.

The previous prime is 656721409. The next prime is 656721427. The reversal of 656721412 is 214127656.

It is an alternating number because its digits alternate between even and odd.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26764 + ... + 45052.

It is an arithmetic number, because the mean of its divisors is an integer number (49163520).

Almost surely, 2^656721412 is an apocalyptic number.

It is an amenable number.

656721412 is a deficient number, since it is larger than the sum of its proper divisors (523203068).

656721412 is a wasteful number, since it uses less digits than its factorization.

656721412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18531 (or 18529 counting only the distinct ones).

The product of its digits is 20160, while the sum is 34.

The square root of 656721412 is about 25626.5762832260. The cubic root of 656721412 is about 869.2146927722.

The spelling of 656721412 in words is "six hundred fifty-six million, seven hundred twenty-one thousand, four hundred twelve".