21186572 has 12 divisors (see below), whose sum is σ = 40447176. Its totient is φ = 9630240.

The previous prime is 21186569. The next prime is 21186587. The reversal of 21186572 is 27568112.

It is a super-2 number, since 2×21186572² = 897741666222368, which contains 22 as substring.

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, 240713 + ... + 240800.

It is an arithmetic number, because the mean of its divisors is an integer number (3370598).

Almost surely, 2^21186572 is an apocalyptic number.

21186572 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21186572 is a deficient number, since it is larger than the sum of its proper divisors (19260604).

21186572 is a wasteful number, since it uses less digits than its factorization.

21186572 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481528 (or 481526 counting only the distinct ones).

The product of its digits is 6720, while the sum is 32.

The square root of 21186572 is about 4602.8873546938. The cubic root of 21186572 is about 276.7070543127.

The spelling of 21186572 in words is "twenty-one million, one hundred eighty-six thousand, five hundred seventy-two".