21311020002 has 64 divisors (see below), whose sum is σ = 43496893440. Its totient is φ = 6959908800.

The previous prime is 21311019997. The next prime is 21311020039. The reversal of 21311020002 is 20002011312.

It is a self number, because there is not a number n which added to its sum of digits gives 21311020002.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 23188899 + ... + 23189817.

It is an arithmetic number, because the mean of its divisors is an integer number (679638960).

Almost surely, 2^21311020002 is an apocalyptic number.

21311020002 is an abundant number, since it is smaller than the sum of its proper divisors (22185873438).

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

21311020002 is a wasteful number, since it uses less digits than its factorization.

21311020002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1399.

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 21311020002 its reverse (20002011312), we get a palindrome (41313031314).

The spelling of 21311020002 in words is "twenty-one billion, three hundred eleven million, twenty thousand, two".