21984831 has 32 divisors (see below), whose sum is σ = 36019200. Its totient is φ = 13141440.

The previous prime is 21984829. The next prime is 21984857. The reversal of 21984831 is 13848912.

It is not a de Polignac number, because 21984831 - 2¹ = 21984829 is a prime.

It is a super-2 number, since 2×21984831² = 966665588197122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21984811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 22995 + ... + 23931.

It is an arithmetic number, because the mean of its divisors is an integer number (1125600).

Almost surely, 2^21984831 is an apocalyptic number.

21984831 is a deficient number, since it is larger than the sum of its proper divisors (14034369).

21984831 is a wasteful number, since it uses less digits than its factorization.

21984831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1036 (or 1030 counting only the distinct ones).

The product of its digits is 13824, while the sum is 36.

The square root of 21984831 is about 4688.7984601601. The cubic root of 21984831 is about 280.1395180546.

The spelling of 21984831 in words is "twenty-one million, nine hundred eighty-four thousand, eight hundred thirty-one".