21373280 has 24 divisors (see below), whose sum is σ = 50494752. Its totient is φ = 8549248.

The previous prime is 21373277. The next prime is 21373327. The reversal of 21373280 is 8237312.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66632 + ... + 66951.

It is an arithmetic number, because the mean of its divisors is an integer number (2103948).

Almost surely, 2^21373280 is an apocalyptic number.

21373280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21373280 is an abundant number, since it is smaller than the sum of its proper divisors (29121472).

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

21373280 is a wasteful number, since it uses less digits than its factorization.

21373280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133598 (or 133590 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 26.

The square root of 21373280 is about 4623.1244845883. The cubic root of 21373280 is about 277.5175110017.

The spelling of 21373280 in words is "twenty-one million, three hundred seventy-three thousand, two hundred eighty".