21164976 has 100 divisors (see below), whose sum is σ = 70038672. Its totient is φ = 6044544.

The previous prime is 21164953. The next prime is 21164989. The reversal of 21164976 is 67946112.

21164976 is a `hidden beast` number, since 2 + 1 + 1 + 649 + 7 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 21164976.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 7906 + ... + 10238.

Almost surely, 2^21164976 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21164976, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35019336).

21164976 is an abundant number, since it is smaller than the sum of its proper divisors (48873696).

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

21164976 is a wasteful number, since it uses less digits than its factorization.

21164976 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2360 (or 2345 counting only the distinct ones).

The product of its digits is 18144, while the sum is 36.

The square root of 21164976 is about 4600.5408377711. The cubic root of 21164976 is about 276.6130042211.

The spelling of 21164976 in words is "twenty-one million, one hundred sixty-four thousand, nine hundred seventy-six".