21913376 has 12 divisors (see below), whose sum is σ = 43142022. Its totient is φ = 10956672.

The previous prime is 21913363. The next prime is 21913379. The reversal of 21913376 is 67331912.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 21864976 + 48400 = 4676^2 + 220^2 .

It is a Harshad number since it is a multiple of its sum of digits (32), and also a Moran number because the ratio is a prime number: 684793 = 21913376 / (2 + 1 + 9 + 1 + 3 + 3 + 7 + 6).

It is not an unprimeable number, because it can be changed into a prime (21913379) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342365 + ... + 342428.

Almost surely, 2^21913376 is an apocalyptic number.

It is an amenable number.

21913376 is a deficient number, since it is larger than the sum of its proper divisors (21228646).

21913376 is an equidigital number, since it uses as much as digits as its factorization.

21913376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 684803 (or 684795 counting only the distinct ones).

The product of its digits is 6804, while the sum is 32.

The square root of 21913376 is about 4681.1725026963. The cubic root of 21913376 is about 279.8356859064.

The spelling of 21913376 in words is "twenty-one million, nine hundred thirteen thousand, three hundred seventy-six".