21898080 has 192 divisors, whose sum is σ = 79289280. Its totient is φ = 5640192.

The previous prime is 21898067. The next prime is 21898087. The reversal of 21898080 is 8089812.

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 (21898087) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 159772 + ... + 159908.

It is an arithmetic number, because the mean of its divisors is an integer number (412965).

Almost surely, 2^21898080 is an apocalyptic number.

21898080 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 21898080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39644640).

21898080 is an abundant number, since it is smaller than the sum of its proper divisors (57391200).

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

21898080 is a wasteful number, since it uses less digits than its factorization.

21898080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198 (or 184 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The square root of 21898080 is about 4679.5384387779. The cubic root of 21898080 is about 279.7705603415.

The spelling of 21898080 in words is "twenty-one million, eight hundred ninety-eight thousand, eighty".