21897712 has 20 divisors (see below), whose sum is σ = 42503976. Its totient is φ = 10928960.

The previous prime is 21897703. The next prime is 21897763. The reversal of 21897712 is 21779812.

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, 12303 + ... + 13969.

Almost surely, 2^21897712 is an apocalyptic number.

It is an amenable number.

21897712 is a deficient number, since it is larger than the sum of its proper divisors (20606264).

21897712 is a wasteful number, since it uses less digits than its factorization.

21897712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2496 (or 2490 counting only the distinct ones).

The product of its digits is 14112, while the sum is 37.

The square root of 21897712 is about 4679.4991184955. The cubic root of 21897712 is about 279.7689931396.

The spelling of 21897712 in words is "twenty-one million, eight hundred ninety-seven thousand, seven hundred twelve".