21130020444 has 48 divisors (see below), whose sum is σ = 53107352480. Its totient is φ = 6500148480.

The previous prime is 21130020433. The next prime is 21130020449. The reversal of 21130020444 is 44402003112.

It is a self number, because there is not a number n which added to its sum of digits gives 21130020444.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21130020449) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 896442 + ... + 919710.

Almost surely, 2^21130020444 is an apocalyptic number.

It is an amenable number.

21130020444 is an abundant number, since it is smaller than the sum of its proper divisors (31977332036).

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

21130020444 is a wasteful number, since it uses less digits than its factorization.

21130020444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29110 (or 29108 counting only the distinct ones).

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

Adding to 21130020444 its reverse (44402003112), we get a palindrome (65532023556).

The spelling of 21130020444 in words is "twenty-one billion, one hundred thirty million, twenty thousand, four hundred forty-four".