21431044 has 24 divisors (see below), whose sum is σ = 38900736. Its totient is φ = 10320000.

The previous prime is 21431023. The next prime is 21431057. The reversal of 21431044 is 44013412.

It is a hoax number, since the sum of its digits (19) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

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, 49509 + ... + 49939.

It is an arithmetic number, because the mean of its divisors is an integer number (1620864).

Almost surely, 2^21431044 is an apocalyptic number.

It is an amenable number.

21431044 is a deficient number, since it is larger than the sum of its proper divisors (17469692).

21431044 is a wasteful number, since it uses less digits than its factorization.

21431044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 867 (or 865 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 21431044 is about 4629.3675593973. The cubic root of 21431044 is about 277.7672948696.

Adding to 21431044 its reverse (44013412), we get a palindrome (65444456).

The spelling of 21431044 in words is "twenty-one million, four hundred thirty-one thousand, forty-four".