21345306256 has 10 divisors (see below), whose sum is σ = 41356530902. Its totient is φ = 10672653120.

The previous prime is 21345306251. The next prime is 21345306313. The reversal of 21345306256 is 65260354312.

It can be written as a sum of positive squares in only one way, i.e., 17503290000 + 3842016256 = 132300^2 + 61984^2 .

It is not an unprimeable number, because it can be changed into a prime (21345306251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 667040805 + ... + 667040836.

Almost surely, 2^21345306256 is an apocalyptic number.

It is an amenable number.

21345306256 is a deficient number, since it is larger than the sum of its proper divisors (20011224646).

21345306256 is a wasteful number, since it uses less digits than its factorization.

21345306256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1334081649 (or 1334081643 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 37.

The spelling of 21345306256 in words is "twenty-one billion, three hundred forty-five million, three hundred six thousand, two hundred fifty-six".