21772568 has 16 divisors (see below), whose sum is σ = 40875000. Its totient is φ = 10872576.

The previous prime is 21772567. The next prime is 21772579. The reversal of 21772568 is 86527712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21772561) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8903 + ... + 11081.

Almost surely, 2^21772568 is an apocalyptic number.

It is an amenable number.

21772568 is a deficient number, since it is larger than the sum of its proper divisors (19102432).

21772568 is a wasteful number, since it uses less digits than its factorization.

21772568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3434 (or 3430 counting only the distinct ones).

The product of its digits is 47040, while the sum is 38.

The square root of 21772568 is about 4666.1084428033. The cubic root of 21772568 is about 279.2350207711.

The spelling of 21772568 in words is "twenty-one million, seven hundred seventy-two thousand, five hundred sixty-eight".