21604328806 has 4 divisors (see below), whose sum is σ = 32406493212. Its totient is φ = 10802164402.

The previous prime is 21604328797. The next prime is 21604328819. The reversal of 21604328806 is 60882340612.

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

It is a super-2 number, since 2×21604328806² (a number of 21 digits) contains 22 as substring.

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, 5401082200 + ... + 5401082203.

It is an arithmetic number, because the mean of its divisors is an integer number (8101623303).

Almost surely, 2^21604328806 is an apocalyptic number.

21604328806 is a deficient number, since it is larger than the sum of its proper divisors (10802164406).

21604328806 is a wasteful number, since it uses less digits than its factorization.

21604328806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10802164405.

The product of its (nonzero) digits is 110592, while the sum is 40.

The spelling of 21604328806 in words is "twenty-one billion, six hundred four million, three hundred twenty-eight thousand, eight hundred six".