21691376 has 40 divisors (see below), whose sum is σ = 48267744. Its totient is φ = 9250560.

The previous prime is 21691357. The next prime is 21691379. The reversal of 21691376 is 67319612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21691379) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32486 + ... + 33146.

Almost surely, 2^21691376 is an apocalyptic number.

It is an amenable number.

21691376 is an abundant number, since it is smaller than the sum of its proper divisors (26576368).

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

21691376 is a wasteful number, since it uses less digits than its factorization.

21691376 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 969 (or 963 counting only the distinct ones).

The product of its digits is 13608, while the sum is 35.

The square root of 21691376 is about 4657.4001331215. The cubic root of 21691376 is about 278.8874903385.

The spelling of 21691376 in words is "twenty-one million, six hundred ninety-one thousand, three hundred seventy-six".