21572612 has 6 divisors (see below), whose sum is σ = 37752078. Its totient is φ = 10786304.

The previous prime is 21572611. The next prime is 21572623. The reversal of 21572612 is 21627512.

It can be written as a sum of positive squares in only one way, i.e., 19219456 + 2353156 = 4384^2 + 1534^2 .

It is not an unprimeable number, because it can be changed into a prime (21572611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2696573 + ... + 2696580.

It is an arithmetic number, because the mean of its divisors is an integer number (6292013).

Almost surely, 2^21572612 is an apocalyptic number.

It is an amenable number.

21572612 is a deficient number, since it is larger than the sum of its proper divisors (16179466).

21572612 is a wasteful number, since it uses less digits than its factorization.

21572612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5393157 (or 5393155 counting only the distinct ones).

The product of its digits is 1680, while the sum is 26.

The square root of 21572612 is about 4644.6326011860. The cubic root of 21572612 is about 278.3775729776.

It can be divided in two parts, 215 and 72612, that added together give a palindrome (72827).

The spelling of 21572612 in words is "twenty-one million, five hundred seventy-two thousand, six hundred twelve".