16520765 has 4 divisors (see below), whose sum is σ = 19824924. Its totient is φ = 13216608.

The previous prime is 16520741. The next prime is 16520771. The reversal of 16520765 is 56702561.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 4831204 + 11689561 = 2198^2 + 3419^2 .

It is a cyclic number.

It is not a de Polignac number, because 16520765 - 2¹⁴ = 16504381 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1652072 + ... + 1652081.

It is an arithmetic number, because the mean of its divisors is an integer number (4956231).

Almost surely, 2^16520765 is an apocalyptic number.

It is an amenable number.

16520765 is a deficient number, since it is larger than the sum of its proper divisors (3304159).

16520765 is an equidigital number, since it uses as much as digits as its factorization.

16520765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3304158.

The product of its (nonzero) digits is 12600, while the sum is 32.

The square root of 16520765 is about 4064.5743934636. The cubic root of 16520765 is about 254.6889196478.

The spelling of 16520765 in words is "sixteen million, five hundred twenty thousand, seven hundred sixty-five".