21604199 has 8 divisors (see below), whose sum is σ = 22623072. Its totient is φ = 20592000.

The previous prime is 21604181. The next prime is 21604213. The reversal of 21604199 is 99140612.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21604199 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21604109) 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, 5699 + ... + 8699.

It is an arithmetic number, because the mean of its divisors is an integer number (2827884).

Almost surely, 2^21604199 is an apocalyptic number.

21604199 is a deficient number, since it is larger than the sum of its proper divisors (1018873).

21604199 is a wasteful number, since it uses less digits than its factorization.

21604199 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3337.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 21604199 is about 4648.0317339708. The cubic root of 21604199 is about 278.5133751730.

The spelling of 21604199 in words is "twenty-one million, six hundred four thousand, one hundred ninety-nine".