21903106656 has 24 divisors (see below), whose sum is σ = 57495655224. Its totient is φ = 7301035520.

The previous prime is 21903106649. The next prime is 21903106657. The reversal of 21903106656 is 65660130912.

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×21903106656² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21903106657) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 114078585 + ... + 114078776.

It is an arithmetic number, because the mean of its divisors is an integer number (2395652301).

Almost surely, 2^21903106656 is an apocalyptic number.

It is an amenable number.

21903106656 is an abundant number, since it is smaller than the sum of its proper divisors (35592548568).

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

21903106656 is a wasteful number, since it uses less digits than its factorization.

21903106656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228157374 (or 228157366 counting only the distinct ones).

The product of its (nonzero) digits is 58320, while the sum is 39.

The spelling of 21903106656 in words is "twenty-one billion, nine hundred three million, one hundred six thousand, six hundred fifty-six".