21312514856 has 16 divisors (see below), whose sum is σ = 40372935540. Its totient is φ = 10546398720.

The previous prime is 21312514837. The next prime is 21312514859. The reversal of 21312514856 is 65841521312.

It can be written as a sum of positive squares in 2 ways, for example, as 17964040900 + 3348473956 = 134030^2 + 57866^2 .

It is not an unprimeable number, because it can be changed into a prime (21312514859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13731515 + ... + 13733066.

Almost surely, 2^21312514856 is an apocalyptic number.

It is an amenable number.

21312514856 is a deficient number, since it is larger than the sum of its proper divisors (19060420684).

21312514856 is a wasteful number, since it uses less digits than its factorization.

21312514856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27464684 (or 27464680 counting only the distinct ones).

The product of its digits is 57600, while the sum is 38.

The spelling of 21312514856 in words is "twenty-one billion, three hundred twelve million, five hundred fourteen thousand, eight hundred fifty-six".