21216088 has 8 divisors (see below), whose sum is σ = 39780180. Its totient is φ = 10608040.

The previous prime is 21216073. The next prime is 21216127. The reversal of 21216088 is 88061212.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1325998 + ... + 1326013.

Almost surely, 2^21216088 is an apocalyptic number.

It is an amenable number.

21216088 is a deficient number, since it is larger than the sum of its proper divisors (18564092).

21216088 is a wasteful number, since it uses less digits than its factorization.

21216088 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2652017 (or 2652013 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 28.

The square root of 21216088 is about 4606.0924871305. The cubic root of 21216088 is about 276.8354925141.

The spelling of 21216088 in words is "twenty-one million, two hundred sixteen thousand, eighty-eight".