21275123043256 has 8 divisors (see below), whose sum is σ = 39890855706120. Its totient is φ = 10637561521624.

The previous prime is 21275123043247. The next prime is 21275123043277. The reversal of 21275123043256 is 65234032157212.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1329695190196 + ... + 1329695190211.

It is an arithmetic number, because the mean of its divisors is an integer number (4986356963265).

Almost surely, 2^{21275123043256} is an apocalyptic number.

It is an amenable number.

21275123043256 is a deficient number, since it is larger than the sum of its proper divisors (18615732662864).

21275123043256 is a wasteful number, since it uses less digits than its factorization.

21275123043256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2659390380413 (or 2659390380409 counting only the distinct ones).

The product of its (nonzero) digits is 604800, while the sum is 43.

The spelling of 21275123043256 in words is "twenty-one trillion, two hundred seventy-five billion, one hundred twenty-three million, forty-three thousand, two hundred fifty-six".