21550604 has 6 divisors (see below), whose sum is σ = 37713564. Its totient is φ = 10775300.

The previous prime is 21550601. The next prime is 21550637. The reversal of 21550604 is 40605512.

It is a self number, because there is not a number n which added to its sum of digits gives 21550604.

It is not an unprimeable number, because it can be changed into a prime (21550601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2693822 + ... + 2693829.

It is an arithmetic number, because the mean of its divisors is an integer number (6285594).

Almost surely, 2^21550604 is an apocalyptic number.

It is an amenable number.

21550604 is a deficient number, since it is larger than the sum of its proper divisors (16162960).

21550604 is a wasteful number, since it uses less digits than its factorization.

21550604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5387655 (or 5387653 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 21550604 is about 4642.2628103114. The cubic root of 21550604 is about 278.2828754633.

The spelling of 21550604 in words is "twenty-one million, five hundred fifty thousand, six hundred four".