21522772 has 12 divisors (see below), whose sum is σ = 37719220. Its totient is φ = 10745856.

The previous prime is 21522749. The next prime is 21522791. The reversal of 21522772 is 27722512.

It can be written as a sum of positive squares in 2 ways, for example, as 7639696 + 13883076 = 2764^2 + 3726^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21522772.

It is a congruent number.

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, 423 + ... + 6574.

Almost surely, 2^21522772 is an apocalyptic number.

It is an amenable number.

21522772 is a deficient number, since it is larger than the sum of its proper divisors (16196448).

21522772 is a wasteful number, since it uses less digits than its factorization.

21522772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7770 (or 7768 counting only the distinct ones).

The product of its digits is 3920, while the sum is 28.

The square root of 21522772 is about 4639.2641657918. The cubic root of 21522772 is about 278.1630256808.

The spelling of 21522772 in words is "twenty-one million, five hundred twenty-two thousand, seven hundred seventy-two".