21107998 has 16 divisors (see below), whose sum is σ = 32868000. Its totient is φ = 10154592.

The previous prime is 21107987. The next prime is 21108007. The reversal of 21107998 is 89970112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25048 + ... + 25876.

It is an arithmetic number, because the mean of its divisors is an integer number (2054250).

Almost surely, 2^21107998 is an apocalyptic number.

21107998 is a deficient number, since it is larger than the sum of its proper divisors (11760002).

21107998 is a wasteful number, since it uses less digits than its factorization.

21107998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1299.

The product of its (nonzero) digits is 9072, while the sum is 37.

The square root of 21107998 is about 4594.3441316471. The cubic root of 21107998 is about 276.3645588625.

The spelling of 21107998 in words is "twenty-one million, one hundred seven thousand, nine hundred ninety-eight".