21546772 has 12 divisors (see below), whose sum is σ = 40607476. Its totient is φ = 9944640.

The previous prime is 21546751. The next prime is 21546781. The reversal of 21546772 is 27764512.

It can be written as a sum of positive squares in 2 ways, for example, as 12702096 + 8844676 = 3564^2 + 2974^2 .

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, 207129 + ... + 207232.

Almost surely, 2^21546772 is an apocalyptic number.

It is an amenable number.

21546772 is a deficient number, since it is larger than the sum of its proper divisors (19060704).

21546772 is a wasteful number, since it uses less digits than its factorization.

21546772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 414378 (or 414376 counting only the distinct ones).

The product of its digits is 23520, while the sum is 34.

The square root of 21546772 is about 4641.8500622058. The cubic root of 21546772 is about 278.2663802846.

The spelling of 21546772 in words is "twenty-one million, five hundred forty-six thousand, seven hundred seventy-two".