21131221010 has 32 divisors (see below), whose sum is σ = 38491930944. Its totient is φ = 8351560000.

The previous prime is 21131220989. The next prime is 21131221063. The reversal of 21131221010 is 1012213112.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 474605 + ... + 517215.

It is an arithmetic number, because the mean of its divisors is an integer number (1202872842).

Almost surely, 2^21131221010 is an apocalyptic number.

21131221010 is a deficient number, since it is larger than the sum of its proper divisors (17360709934).

21131221010 is a wasteful number, since it uses less digits than its factorization.

21131221010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43210.

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 21131221010 its reverse (1012213112), we get a palindrome (22143434122).

The spelling of 21131221010 in words is "twenty-one billion, one hundred thirty-one million, two hundred twenty-one thousand, ten".