16604813 has 4 divisors (see below), whose sum is σ = 16627068. Its totient is φ = 16582560.

The previous prime is 16604807. The next prime is 16604821. The reversal of 16604813 is 31840661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31840661 = 1171 ⋅27191.

It can be written as a sum of positive squares in 2 ways, for example, as 5866084 + 10738729 = 2422^2 + 3277^2 .

It is a cyclic number.

It is not a de Polignac number, because 16604813 - 2¹⁰ = 16603789 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 (16604843) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9968 + ... + 11513.

It is an arithmetic number, because the mean of its divisors is an integer number (4156767).

Almost surely, 2^16604813 is an apocalyptic number.

It is an amenable number.

16604813 is a deficient number, since it is larger than the sum of its proper divisors (22255).

16604813 is an equidigital number, since it uses as much as digits as its factorization.

16604813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22254.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 16604813 is about 4074.9003668802. The cubic root of 16604813 is about 255.1200920946.

The spelling of 16604813 in words is "sixteen million, six hundred four thousand, eight hundred thirteen".