21244572 has 24 divisors (see below), whose sum is σ = 55078800. Its totient is φ = 7081488.

The previous prime is 21244507. The next prime is 21244583. The reversal of 21244572 is 27544212.

21244572 is a `hidden beast` number, since 212 + 445 + 7 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 98247 + ... + 98462.

It is an arithmetic number, because the mean of its divisors is an integer number (2294950).

Almost surely, 2^21244572 is an apocalyptic number.

It is an amenable number.

21244572 is an abundant number, since it is smaller than the sum of its proper divisors (33834228).

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

21244572 is a wasteful number, since it uses less digits than its factorization.

21244572 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196722 (or 196714 counting only the distinct ones).

The product of its digits is 4480, while the sum is 27.

The square root of 21244572 is about 4609.1834417823. The cubic root of 21244572 is about 276.9593270921.

Adding to 21244572 its reverse (27544212), we get a palindrome (48788784).

The spelling of 21244572 in words is "twenty-one million, two hundred forty-four thousand, five hundred seventy-two".