21798938 has 8 divisors (see below), whose sum is σ = 37369632. Its totient is φ = 9342396.

The previous prime is 21798911. The next prime is 21798961. The reversal of 21798938 is 83989712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21798892 and 21798901.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 778520 + ... + 778547.

It is an arithmetic number, because the mean of its divisors is an integer number (4671204).

Almost surely, 2^21798938 is an apocalyptic number.

21798938 is a deficient number, since it is larger than the sum of its proper divisors (15570694).

21798938 is a wasteful number, since it uses less digits than its factorization.

21798938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1557076.

The product of its digits is 217728, while the sum is 47.

The square root of 21798938 is about 4668.9332828816. The cubic root of 21798938 is about 279.3477077807.

The spelling of 21798938 in words is "twenty-one million, seven hundred ninety-eight thousand, nine hundred thirty-eight".