21676572 has 72 divisors (see below), whose sum is σ = 58858800. Its totient is φ = 6967296.

The previous prime is 21676553. The next prime is 21676579. The reversal of 21676572 is 27567612.

21676572 is a `hidden beast` number, since 2 + 16 + 76 + 572 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21676579) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 27804 + ... + 28572.

Almost surely, 2^21676572 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21676572, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29429400).

21676572 is an abundant number, since it is smaller than the sum of its proper divisors (37182228).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21676572 is a wasteful number, since it uses less digits than its factorization.

21676572 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 817 (or 803 counting only the distinct ones).

The product of its digits is 35280, while the sum is 36.

The square root of 21676572 is about 4655.8105631565. The cubic root of 21676572 is about 278.8240305560.

The spelling of 21676572 in words is "twenty-one million, six hundred seventy-six thousand, five hundred seventy-two".