21131044 has 24 divisors (see below), whose sum is σ = 40507488. Its totient is φ = 9565440.

The previous prime is 21131041. The next prime is 21131069. The reversal of 21131044 is 44013112.

It is not an unprimeable number, because it can be changed into a prime (21131041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11604 + ... + 13300.

It is an arithmetic number, because the mean of its divisors is an integer number (1687812).

Almost surely, 2^21131044 is an apocalyptic number.

It is an amenable number.

21131044 is a deficient number, since it is larger than the sum of its proper divisors (19376444).

21131044 is a wasteful number, since it uses less digits than its factorization.

21131044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1995 (or 1993 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 21131044 is about 4596.8515312113. The cubic root of 21131044 is about 276.4651018111.

Adding to 21131044 its reverse (44013112), we get a palindrome (65144156).

The spelling of 21131044 in words is "twenty-one million, one hundred thirty-one thousand, forty-four".