21813230 has 32 divisors (see below), whose sum is σ = 40769568. Its totient is φ = 8396800.

The previous prime is 21813179. The next prime is 21813247. The reversal of 21813230 is 3231812.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33710 + ... + 34350.

It is an arithmetic number, because the mean of its divisors is an integer number (1274049).

Almost surely, 2^21813230 is an apocalyptic number.

21813230 is a deficient number, since it is larger than the sum of its proper divisors (18956338).

21813230 is a wasteful number, since it uses less digits than its factorization.

21813230 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 772.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 21813230 is about 4670.4635744217. The cubic root of 21813230 is about 279.4087438618.

The spelling of 21813230 in words is "twenty-one million, eight hundred thirteen thousand, two hundred thirty".