21604118 has 4 divisors (see below), whose sum is σ = 32406180. Its totient is φ = 10802058.

The previous prime is 21604109. The next prime is 21604139. The reversal of 21604118 is 81140612.

It is a semiprime because it is the product of two primes.

It is a junction number, because it is equal to n+sod(n) for n = 21604093 and 21604102.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5401028 + ... + 5401031.

It is an arithmetic number, because the mean of its divisors is an integer number (8101545).

Almost surely, 2^21604118 is an apocalyptic number.

21604118 is a deficient number, since it is larger than the sum of its proper divisors (10802062).

21604118 is a wasteful number, since it uses less digits than its factorization.

21604118 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10802061.

The product of its (nonzero) digits is 384, while the sum is 23.

The square root of 21604118 is about 4648.0230205970. The cubic root of 21604118 is about 278.5130270985.

The spelling of 21604118 in words is "twenty-one million, six hundred four thousand, one hundred eighteen".