21818364 has 24 divisors (see below), whose sum is σ = 50989008. Its totient is φ = 7261440.

The previous prime is 21818359. The next prime is 21818393. The reversal of 21818364 is 46381812.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10794 + ... + 12654.

It is an arithmetic number, because the mean of its divisors is an integer number (2124542).

Almost surely, 2^21818364 is an apocalyptic number.

It is an amenable number.

21818364 is an abundant number, since it is smaller than the sum of its proper divisors (29170644).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21818364 is a wasteful number, since it uses less digits than its factorization.

21818364 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2845 (or 2843 counting only the distinct ones).

The product of its digits is 9216, while the sum is 33.

The square root of 21818364 is about 4671.0131663270. The cubic root of 21818364 is about 279.4306628526.

The spelling of 21818364 in words is "twenty-one million, eight hundred eighteen thousand, three hundred sixty-four".