21020657012 has 24 divisors (see below), whose sum is σ = 38964416904. Its totient is φ = 9888422912.

The previous prime is 21020657003. The next prime is 21020657023. The reversal of 21020657012 is 21075602012.

It can be written as a sum of positive squares in 4 ways, for example, as 5347119376 + 15673537636 = 73124^2 + 125194^2 .

It is a super-2 number, since 2×21020657012² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 133178 + ... + 244494.

It is an arithmetic number, because the mean of its divisors is an integer number (1623517371).

Almost surely, 2^21020657012 is an apocalyptic number.

It is an amenable number.

21020657012 is a deficient number, since it is larger than the sum of its proper divisors (17943759892).

21020657012 is a wasteful number, since it uses less digits than its factorization.

21020657012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114115 (or 114113 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 26.

The spelling of 21020657012 in words is "twenty-one billion, twenty million, six hundred fifty-seven thousand, twelve".