21808088 has 16 divisors (see below), whose sum is σ = 40966080. Its totient is φ = 10883808.

The previous prime is 21808081. The next prime is 21808091. The reversal of 21808088 is 88080812.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21808081) 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, 2681 + ... + 7127.

It is an arithmetic number, because the mean of its divisors is an integer number (2560380).

Almost surely, 2^21808088 is an apocalyptic number.

It is an amenable number.

21808088 is a deficient number, since it is larger than the sum of its proper divisors (19157992).

21808088 is a wasteful number, since it uses less digits than its factorization.

21808088 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5066 (or 5062 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 35.

The square root of 21808088 is about 4669.9130612893. The cubic root of 21808088 is about 279.3867872683.

The spelling of 21808088 in words is "twenty-one million, eight hundred eight thousand, eighty-eight".