21140044 has 12 divisors (see below), whose sum is σ = 39171384. Its totient is φ = 9948224.

The previous prime is 21140033. The next prime is 21140069. The reversal of 21140044 is 44004112.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 155374 + ... + 155509.

It is an arithmetic number, because the mean of its divisors is an integer number (3264282).

Almost surely, 2^21140044 is an apocalyptic number.

It is an amenable number.

21140044 is a deficient number, since it is larger than the sum of its proper divisors (18031340).

21140044 is a wasteful number, since it uses less digits than its factorization.

21140044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310904 (or 310902 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 21140044 is about 4597.8303578971. The cubic root of 21140044 is about 276.5043463265.

Adding to 21140044 its reverse (44004112), we get a palindrome (65144156).

The spelling of 21140044 in words is "twenty-one million, one hundred forty thousand, forty-four".