21298880 has 56 divisors (see below), whose sum is σ = 51297840. Its totient is φ = 8422400.

The previous prime is 21298877. The next prime is 21298883. The reversal of 21298880 is 8889212.

It is an interprime number because it is at equal distance from previous prime (21298877) and next prime (21298883).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21298883) 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, 31991 + ... + 32649.

Almost surely, 2^21298880 is an apocalyptic number.

21298880 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 21298880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25648920).

21298880 is an abundant number, since it is smaller than the sum of its proper divisors (29998960).

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

21298880 is a wasteful number, since it uses less digits than its factorization.

21298880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 777 (or 767 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 38.

The square root of 21298880 is about 4615.0709637014. The cubic root of 21298880 is about 277.1951254984.

The spelling of 21298880 in words is "twenty-one million, two hundred ninety-eight thousand, eight hundred eighty".