21866088 has 16 divisors (see below), whose sum is σ = 54665280. Its totient is φ = 7288688.

The previous prime is 21866081. The next prime is 21866111. The reversal of 21866088 is 88066812.

It is not an unprimeable number, because it can be changed into a prime (21866081) 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, 455520 + ... + 455567.

It is an arithmetic number, because the mean of its divisors is an integer number (3416580).

Almost surely, 2^21866088 is an apocalyptic number.

It is an amenable number.

21866088 is an abundant number, since it is smaller than the sum of its proper divisors (32799192).

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

21866088 is a wasteful number, since it uses less digits than its factorization.

21866088 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 911096 (or 911092 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 39.

The square root of 21866088 is about 4676.1189035353. The cubic root of 21866088 is about 279.6342503391.

The spelling of 21866088 in words is "twenty-one million, eight hundred sixty-six thousand, eighty-eight".