21131324 has 6 divisors (see below), whose sum is σ = 36979824. Its totient is φ = 10565660.

The previous prime is 21131317. The next prime is 21131333. The reversal of 21131324 is 42313112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2641412 + ... + 2641419.

It is an arithmetic number, because the mean of its divisors is an integer number (6163304).

Almost surely, 2^21131324 is an apocalyptic number.

It is an amenable number.

21131324 is a deficient number, since it is larger than the sum of its proper divisors (15848500).

21131324 is a wasteful number, since it uses less digits than its factorization.

21131324 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5282835 (or 5282833 counting only the distinct ones).

The product of its digits is 144, while the sum is 17.

The square root of 21131324 is about 4596.8819867384. The cubic root of 21131324 is about 276.4663229195.

Adding to 21131324 its reverse (42313112), we get a palindrome (63444436).

The spelling of 21131324 in words is "twenty-one million, one hundred thirty-one thousand, three hundred twenty-four".