21367520 has 48 divisors (see below), whose sum is σ = 51120720. Its totient is φ = 8438784.

The previous prime is 21367501. The next prime is 21367523. The reversal of 21367520 is 2576312.

It is a self number, because there is not a number n which added to its sum of digits gives 21367520.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21367523) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12476 + ... + 14084.

It is an arithmetic number, because the mean of its divisors is an integer number (1065015).

Almost surely, 2^21367520 is an apocalyptic number.

21367520 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 21367520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25560360).

21367520 is an abundant number, since it is smaller than the sum of its proper divisors (29753200).

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

21367520 is a wasteful number, since it uses less digits than its factorization.

21367520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1707 (or 1699 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 26.

The square root of 21367520 is about 4622.5014872902. The cubic root of 21367520 is about 277.4925788671.

The spelling of 21367520 in words is "twenty-one million, three hundred sixty-seven thousand, five hundred twenty".