21021111221010 has 64 divisors (see below), whose sum is σ = 53375538902400. Its totient is φ = 5283639148032.

The previous prime is 21021111220987. The next prime is 21021111221057. The reversal of 21021111221010 is 1012211112012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

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, 93489595 + ... + 93714174.

It is an arithmetic number, because the mean of its divisors is an integer number (833992795350).

Almost surely, 2^{21021111221010} is an apocalyptic number.

21021111221010 is an abundant number, since it is smaller than the sum of its proper divisors (32354427681390).

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

21021111221010 is a wasteful number, since it uses less digits than its factorization.

21021111221010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187203995.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21021111221010 its reverse (1012211112012), we get a palindrome (22033322333022).

The spelling of 21021111221010 in words is "twenty-one trillion, twenty-one billion, one hundred eleven million, two hundred twenty-one thousand, ten".