21163044 has 24 divisors (see below), whose sum is σ = 56435008. Its totient is φ = 6046560.

The previous prime is 21163033. The next prime is 21163057. The reversal of 21163044 is 44036112.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 21163044.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 125887 + ... + 126054.

Almost surely, 2^21163044 is an apocalyptic number.

It is an amenable number.

21163044 is an abundant number, since it is smaller than the sum of its proper divisors (35271964).

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

21163044 is a wasteful number, since it uses less digits than its factorization.

21163044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251955 (or 251953 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 21163044 is about 4600.3308576667. The cubic root of 21163044 is about 276.6045872876.

Adding to 21163044 its reverse (44036112), we get a palindrome (65199156).

The spelling of 21163044 in words is "twenty-one million, one hundred sixty-three thousand, forty-four".