21377492 has 12 divisors (see below), whose sum is σ = 37494996. Its totient is φ = 10664640.

The previous prime is 21377459. The next prime is 21377501. The reversal of 21377492 is 29477312.

It can be written as a sum of positive squares in 2 ways, for example, as 14638276 + 6739216 = 3826^2 + 2596^2 .

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 3953 + ... + 7640.

It is an arithmetic number, because the mean of its divisors is an integer number (3124583).

Almost surely, 2^21377492 is an apocalyptic number.

It is an amenable number.

21377492 is a deficient number, since it is larger than the sum of its proper divisors (16117504).

21377492 is a wasteful number, since it uses less digits than its factorization.

21377492 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12058 (or 12056 counting only the distinct ones).

The product of its digits is 21168, while the sum is 35.

The square root of 21377492 is about 4623.5799982265. The cubic root of 21377492 is about 277.5357397898.

The spelling of 21377492 in words is "twenty-one million, three hundred seventy-seven thousand, four hundred ninety-two".