21115874 has 12 divisors (see below), whose sum is σ = 34298226. Its totient is φ = 9745632.

The previous prime is 21115837. The next prime is 21115879. The reversal of 21115874 is 47851112.

It can be written as a sum of positive squares in 3 ways, for example, as 10843849 + 10272025 = 3293^2 + 3205^2 .

It is not an unprimeable number, because it can be changed into a prime (21115879) 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 5 ways as a sum of consecutive naturals, for example, 30899 + ... + 31574.

Almost surely, 2^21115874 is an apocalyptic number.

21115874 is a deficient number, since it is larger than the sum of its proper divisors (13182352).

21115874 is a wasteful number, since it uses less digits than its factorization.

21115874 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62501 (or 62488 counting only the distinct ones).

The product of its digits is 2240, while the sum is 29.

The square root of 21115874 is about 4595.2011925486. The cubic root of 21115874 is about 276.3989277717.

Adding to 21115874 its reverse (47851112), we get a palindrome (68966986).

The spelling of 21115874 in words is "twenty-one million, one hundred fifteen thousand, eight hundred seventy-four".