21500343512656 has 60 divisors (see below), whose sum is σ = 42159114227700. Its totient is φ = 10622053478400.

The previous prime is 21500343512629. The next prime is 21500343512663. The reversal of 21500343512656 is 65621534300512.

It can be written as a sum of positive squares in 2 ways, for example, as 8755586312256 + 12744757200400 = 2958984^2 + 3569980^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 76074006 + ... + 76356106.

It is an arithmetic number, because the mean of its divisors is an integer number (702651903795).

Almost surely, 2^{21500343512656} is an apocalyptic number.

It is an amenable number.

21500343512656 is a deficient number, since it is larger than the sum of its proper divisors (20658770715044).

21500343512656 is a wasteful number, since it uses less digits than its factorization.

21500343512656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 282764 (or 282655 counting only the distinct ones).

The product of its (nonzero) digits is 648000, while the sum is 43.

The spelling of 21500343512656 in words is "twenty-one trillion, five hundred billion, three hundred forty-three million, five hundred twelve thousand, six hundred fifty-six".