21088364 has 48 divisors (see below), whose sum is σ = 43164576. Its totient is φ = 8983040.

The previous prime is 21088357. The next prime is 21088367. The reversal of 21088364 is 46388012.

It is a self number, because there is not a number n which added to its sum of digits gives 21088364.

It is not an unprimeable number, because it can be changed into a prime (21088367) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 90392 + ... + 90624.

It is an arithmetic number, because the mean of its divisors is an integer number (899262).

Almost surely, 2^21088364 is an apocalyptic number.

It is an amenable number.

21088364 is an abundant number, since it is smaller than the sum of its proper divisors (22076212).

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

21088364 is a wasteful number, since it uses less digits than its factorization.

21088364 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 287 (or 263 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 21088364 is about 4592.2068768730. The cubic root of 21088364 is about 276.2788437222.

The spelling of 21088364 in words is "twenty-one million, eighty-eight thousand, three hundred sixty-four".