21716572 has 6 divisors (see below), whose sum is σ = 38004008. Its totient is φ = 10858284.

The previous prime is 21716567. The next prime is 21716573. The reversal of 21716572 is 27561712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21716573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2714568 + ... + 2714575.

Almost surely, 2^21716572 is an apocalyptic number.

It is an amenable number.

21716572 is a deficient number, since it is larger than the sum of its proper divisors (16287436).

21716572 is a wasteful number, since it uses less digits than its factorization.

21716572 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5429147 (or 5429145 counting only the distinct ones).

The product of its digits is 5880, while the sum is 31.

The square root of 21716572 is about 4660.1042906785. The cubic root of 21716572 is about 278.9954307821.

The spelling of 21716572 in words is "twenty-one million, seven hundred sixteen thousand, five hundred seventy-two".