21115494 has 24 divisors (see below), whose sum is σ = 46815912. Its totient is φ = 6874560.

The previous prime is 21115453. The next prime is 21115511. The reversal of 21115494 is 49451112.

21115494 is a `hidden beast` number, since 2 + 111 + 549 + 4 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12867 + ... + 14414.

It is an arithmetic number, because the mean of its divisors is an integer number (1950663).

Almost surely, 2^21115494 is an apocalyptic number.

21115494 is an abundant number, since it is smaller than the sum of its proper divisors (25700418).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21115494 is a wasteful number, since it uses less digits than its factorization.

21115494 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27332 (or 27329 counting only the distinct ones).

The product of its digits is 1440, while the sum is 27.

The square root of 21115494 is about 4595.1598448803. The cubic root of 21115494 is about 276.3972697422.

It can be divided in two parts, 21115 and 494, that added together give a square (21609 = 147²).

The spelling of 21115494 in words is "twenty-one million, one hundred fifteen thousand, four hundred ninety-four".