21308088 has 16 divisors (see below), whose sum is σ = 53270280. Its totient is φ = 7102688.

The previous prime is 21308081. The next prime is 21308107. The reversal of 21308088 is 88080312.

It is a super-2 number, since 2×21308088² = 908069228431488, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21308081) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 443895 + ... + 443942.

Almost surely, 2^21308088 is an apocalyptic number.

It is an amenable number.

21308088 is an abundant number, since it is smaller than the sum of its proper divisors (31962192).

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

21308088 is a wasteful number, since it uses less digits than its factorization.

21308088 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 887846 (or 887842 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 30.

The square root of 21308088 is about 4616.0684570314. The cubic root of 21308088 is about 277.2350657047.

The spelling of 21308088 in words is "twenty-one million, three hundred eight thousand, eighty-eight".