21012363620 has 12 divisors (see below), whose sum is σ = 44125963644. Its totient is φ = 8404945440.

The previous prime is 21012363607. The next prime is 21012363637. The reversal of 21012363620 is 2636321012.

It can be written as a sum of positive squares in 2 ways, for example, as 7026462976 + 13985900644 = 83824^2 + 118262^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21012363620.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 525309071 + ... + 525309110.

It is an arithmetic number, because the mean of its divisors is an integer number (3677163637).

Almost surely, 2^21012363620 is an apocalyptic number.

21012363620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21012363620 is an abundant number, since it is smaller than the sum of its proper divisors (23113600024).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21012363620 is a wasteful number, since it uses less digits than its factorization.

21012363620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1050618190 (or 1050618188 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 26.

Adding to 21012363620 its reverse (2636321012), we get a palindrome (23648684632).

The spelling of 21012363620 in words is "twenty-one billion, twelve million, three hundred sixty-three thousand, six hundred twenty".