21798868 has 24 divisors (see below), whose sum is σ = 46952192. Its totient is φ = 8623584.

The previous prime is 21798863. The next prime is 21798901. The reversal of 21798868 is 86889712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21798863) 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, 29580 + ... + 30307.

Almost surely, 2^21798868 is an apocalyptic number.

21798868 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21798868 is an abundant number, since it is smaller than the sum of its proper divisors (25153324).

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

21798868 is a wasteful number, since it uses less digits than its factorization.

21798868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59911 (or 59909 counting only the distinct ones).

The product of its digits is 387072, while the sum is 49.

The square root of 21798868 is about 4668.9257865166. The cubic root of 21798868 is about 279.3474087698.

The spelling of 21798868 in words is "twenty-one million, seven hundred ninety-eight thousand, eight hundred sixty-eight".