21898968 has 128 divisors (see below), whose sum is σ = 69457920. Its totient is φ = 5598720.

The previous prime is 21898951. The next prime is 21898993. The reversal of 21898968 is 86989812.

It is a self number, because there is not a number n which added to its sum of digits gives 21898968.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 80673 + ... + 80943.

It is an arithmetic number, because the mean of its divisors is an integer number (542640).

Almost surely, 2^21898968 is an apocalyptic number.

21898968 is a gapful number since it is divisible by the number (28) 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 21898968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34728960).

21898968 is an abundant number, since it is smaller than the sum of its proper divisors (47558952).

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

21898968 is a wasteful number, since it uses less digits than its factorization.

21898968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 337 (or 333 counting only the distinct ones).

The product of its digits is 497664, while the sum is 51.

The square root of 21898968 is about 4679.6333189685. The cubic root of 21898968 is about 279.7743419958.

The spelling of 21898968 in words is "twenty-one million, eight hundred ninety-eight thousand, nine hundred sixty-eight".