21376980 has 96 divisors (see below), whose sum is σ = 68705280. Its totient is φ = 5512320.

The previous prime is 21376951. The next prime is 21376981. The reversal of 21376980 is 8967312.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21376981) 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 in 31 ways as a sum of consecutive naturals, for example, 16102 + ... + 17378.

It is an arithmetic number, because the mean of its divisors is an integer number (715680).

Almost surely, 2^21376980 is an apocalyptic number.

21376980 is a gapful number since it is divisible by the number (20) 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 21376980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34352640).

21376980 is an abundant number, since it is smaller than the sum of its proper divisors (47328300).

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

21376980 is a wasteful number, since it uses less digits than its factorization.

21376980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1326 (or 1318 counting only the distinct ones).

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

The square root of 21376980 is about 4623.5246295440. The cubic root of 21376980 is about 277.5335240726.

The spelling of 21376980 in words is "twenty-one million, three hundred seventy-six thousand, nine hundred eighty".