21132668 has 6 divisors (see below), whose sum is σ = 36982176. Its totient is φ = 10566332.

The previous prime is 21132667. The next prime is 21132689. The reversal of 21132668 is 86623112.

It is a self number, because there is not a number n which added to its sum of digits gives 21132668.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21132667) by changing a digit.

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, 2641580 + ... + 2641587.

It is an arithmetic number, because the mean of its divisors is an integer number (6163696).

Almost surely, 2^21132668 is an apocalyptic number.

It is an amenable number.

21132668 is a deficient number, since it is larger than the sum of its proper divisors (15849508).

21132668 is a wasteful number, since it uses less digits than its factorization.

21132668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5283171 (or 5283169 counting only the distinct ones).

The product of its digits is 3456, while the sum is 29.

The square root of 21132668 is about 4597.0281704597. The cubic root of 21132668 is about 276.4721840897.

The spelling of 21132668 in words is "twenty-one million, one hundred thirty-two thousand, six hundred sixty-eight".