656211656421 has 32 divisors (see below), whose sum is σ = 973549445120. Its totient is φ = 436852060272.

The previous prime is 656211656411. The next prime is 656211656423. The reversal of 656211656421 is 124656112656.

656211656421 is a `hidden beast` number, since 6 + 5 + 6 + 211 + 6 + 5 + 6 + 421 = 666.

656211656421 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 656211656421 - 2⁵ = 656211656389 is a prime.

It is a super-2 number, since 2×656211656421² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (656211656423) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 79411536 + ... + 79419798.

It is an arithmetic number, because the mean of its divisors is an integer number (30423420160).

Almost surely, 2^656211656421 is an apocalyptic number.

It is an amenable number.

656211656421 is a deficient number, since it is larger than the sum of its proper divisors (317337788699).

656211656421 is a wasteful number, since it uses less digits than its factorization.

656211656421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12102 (or 12096 counting only the distinct ones).

The product of its digits is 518400, while the sum is 45.

The spelling of 656211656421 in words is "six hundred fifty-six billion, two hundred eleven million, six hundred fifty-six thousand, four hundred twenty-one".