21553088 has 14 divisors (see below), whose sum is σ = 42769536. Its totient is φ = 10776512.

The previous prime is 21553079. The next prime is 21553099. The reversal of 21553088 is 88035512.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 168320 + ... + 168447.

Almost surely, 2^21553088 is an apocalyptic number.

It is an amenable number.

21553088 is a deficient number, since it is larger than the sum of its proper divisors (21216448).

21553088 is an equidigital number, since it uses as much as digits as its factorization.

21553088 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 336779 (or 336769 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 32.

The square root of 21553088 is about 4642.5303445427. The cubic root of 21553088 is about 278.2935670137.

The spelling of 21553088 in words is "twenty-one million, five hundred fifty-three thousand, eighty-eight".