21897692 has 12 divisors (see below), whose sum is σ = 39044376. Its totient is φ = 10742160.

The previous prime is 21897661. The next prime is 21897703. The reversal of 21897692 is 29679812.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51434 + ... + 51857.

It is an arithmetic number, because the mean of its divisors is an integer number (3253698).

Almost surely, 2^21897692 is an apocalyptic number.

It is an amenable number.

21897692 is a deficient number, since it is larger than the sum of its proper divisors (17146684).

21897692 is a wasteful number, since it uses less digits than its factorization.

21897692 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103348 (or 103346 counting only the distinct ones).

The product of its digits is 108864, while the sum is 44.

The square root of 21897692 is about 4679.4969815141. The cubic root of 21897692 is about 279.7689079650.

The spelling of 21897692 in words is "twenty-one million, eight hundred ninety-seven thousand, six hundred ninety-two".