21798884 has 6 divisors (see below), whose sum is σ = 38148054. Its totient is φ = 10899440.

The previous prime is 21798863. The next prime is 21798901. The reversal of 21798884 is 48889712.

It can be written as a sum of positive squares in only one way, i.e., 15038884 + 6760000 = 3878^2 + 2600^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2724857 + ... + 2724864.

It is an arithmetic number, because the mean of its divisors is an integer number (6358009).

Almost surely, 2^21798884 is an apocalyptic number.

It is an amenable number.

21798884 is a deficient number, since it is larger than the sum of its proper divisors (16349170).

21798884 is a wasteful number, since it uses less digits than its factorization.

21798884 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5449725 (or 5449723 counting only the distinct ones).

The product of its digits is 258048, while the sum is 47.

The square root of 21798884 is about 4668.9274999726. The cubic root of 21798884 is about 279.3474771152.

The spelling of 21798884 in words is "twenty-one million, seven hundred ninety-eight thousand, eight hundred eighty-four".