21210300444 has 48 divisors (see below), whose sum is σ = 53390661408. Its totient is φ = 6528657408.

The previous prime is 21210300421. The next prime is 21210300451. The reversal of 21210300444 is 44400301212.

It is a self number, because there is not a number n which added to its sum of digits gives 21210300444.

It is a congruent number.

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, 970057 + ... + 991680.

It is an arithmetic number, because the mean of its divisors is an integer number (1112305446).

Almost surely, 2^21210300444 is an apocalyptic number.

It is an amenable number.

21210300444 is an abundant number, since it is smaller than the sum of its proper divisors (32180360964).

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

21210300444 is a wasteful number, since it uses less digits than its factorization.

21210300444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1961814 (or 1961812 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

Adding to 21210300444 its product of nonzero digits (768), we get a palindrome (21210301212).

Adding to 21210300444 its reverse (44400301212), we get a palindrome (65610601656).

The spelling of 21210300444 in words is "twenty-one billion, two hundred ten million, three hundred thousand, four hundred forty-four".