21398882 has 6 divisors (see below), whose sum is σ = 32108139. Its totient is φ = 10696170.

The previous prime is 21398873. The next prime is 21398899. The reversal of 21398882 is 28889312.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 10699441 + 10699441 = 3271^2 + 3271^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=3271.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 4907 + ... + 8177.

Almost surely, 2^21398882 is an apocalyptic number.

21398882 is a deficient number, since it is larger than the sum of its proper divisors (10709257).

21398882 is an frugal number, since it uses more digits than its factorization.

21398882 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6544 (or 3273 counting only the distinct ones).

The product of its digits is 55296, while the sum is 41.

The square root of 21398882 is about 4625.8925625224. The cubic root of 21398882 is about 277.6282749757.

The spelling of 21398882 in words is "twenty-one million, three hundred ninety-eight thousand, eight hundred eighty-two".