21476664 has 160 divisors (see below), whose sum is σ = 68999040. Its totient is φ = 6177600.

The previous prime is 21476659. The next prime is 21476671. The reversal of 21476664 is 46667412.

21476664 = 79³ + 80³ + ... + 105³.

It is a super-2 number, since 2×21476664² = 922494193137792, which contains 22 as substring.

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

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 in 39 ways as a sum of consecutive naturals, for example, 163879 + ... + 164009.

It is an arithmetic number, because the mean of its divisors is an integer number (431244).

Almost surely, 2^21476664 is an apocalyptic number.

21476664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21476664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34499520).

21476664 is an abundant number, since it is smaller than the sum of its proper divisors (47522376).

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

21476664 is a wasteful number, since it uses less digits than its factorization.

21476664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183 (or 170 counting only the distinct ones).

The product of its digits is 48384, while the sum is 36.

The square root of 21476664 is about 4634.2921789633. The cubic root of 21476664 is about 277.9642484604.

The spelling of 21476664 in words is "twenty-one million, four hundred seventy-six thousand, six hundred sixty-four".