21138088 has 16 divisors (see below), whose sum is σ = 40027860. Its totient is φ = 10464000.

The previous prime is 21138077. The next prime is 21138101. The reversal of 21138088 is 88083112.

It can be written as a sum of positive squares in 2 ways, for example, as 20593444 + 544644 = 4538^2 + 738^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12273 + ... + 13888.

Almost surely, 2^21138088 is an apocalyptic number.

It is an amenable number.

21138088 is a deficient number, since it is larger than the sum of its proper divisors (18889772).

21138088 is a wasteful number, since it uses less digits than its factorization.

21138088 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26268 (or 26264 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 31.

The square root of 21138088 is about 4597.6176439543. The cubic root of 21138088 is about 276.4958181326.

It can be divided in two parts, 2113 and 8088, that added together give a palindrome (10201).

The spelling of 21138088 in words is "twenty-one million, one hundred thirty-eight thousand, eighty-eight".