21044264 has 16 divisors (see below), whose sum is σ = 41173920. Its totient is φ = 10064560.

The previous prime is 21044263. The next prime is 21044269. The reversal of 21044264 is 46244012.

It is a super-2 number, since 2×21044264² = 885722094603392, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is not an unprimeable number, because it can be changed into a prime (21044263) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57002 + ... + 57369.

It is an arithmetic number, because the mean of its divisors is an integer number (2573370).

Almost surely, 2^21044264 is an apocalyptic number.

It is an amenable number.

21044264 is a deficient number, since it is larger than the sum of its proper divisors (20129656).

21044264 is a wasteful number, since it uses less digits than its factorization.

21044264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114400 (or 114396 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 23.

The square root of 21044264 is about 4587.4027510128. The cubic root of 21044264 is about 276.0861244912.

Adding to 21044264 its reverse (46244012), we get a palindrome (67288276).

The spelling of 21044264 in words is "twenty-one million, forty-four thousand, two hundred sixty-four".