21376368 has 120 divisors (see below), whose sum is σ = 67929680. Its totient is φ = 6220800.

The previous prime is 21376357. The next prime is 21376403. The reversal of 21376368 is 86367312.

It is a happy number.

21376368 is a `hidden beast` number, since 2 + 13 + 7 + 636 + 8 = 666.

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 (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 35268 + ... + 35868.

Almost surely, 2^21376368 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 21376368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33964840).

21376368 is an abundant number, since it is smaller than the sum of its proper divisors (46553312).

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

21376368 is a wasteful number, since it uses less digits than its factorization.

21376368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 647 (or 638 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 21376368 is about 4623.4584457957. The cubic root of 21376368 is about 277.5308755517.

The spelling of 21376368 in words is "twenty-one million, three hundred seventy-six thousand, three hundred sixty-eight".