16505913 has 4 divisors (see below), whose sum is σ = 22007888. Its totient is φ = 11003940.

The previous prime is 16505911. The next prime is 16505921. The reversal of 16505913 is 31950561.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 31950561 = 3 ⋅10650187.

It is not a de Polignac number, because 16505913 - 2¹ = 16505911 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16505911) 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, 2750983 + ... + 2750988.

It is an arithmetic number, because the mean of its divisors is an integer number (5501972).

Almost surely, 2^16505913 is an apocalyptic number.

It is an amenable number.

16505913 is a deficient number, since it is larger than the sum of its proper divisors (5501975).

16505913 is an equidigital number, since it uses as much as digits as its factorization.

16505913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5501974.

The product of its (nonzero) digits is 4050, while the sum is 30.

The square root of 16505913 is about 4062.7469771080. The cubic root of 16505913 is about 254.6125758482.

The spelling of 16505913 in words is "sixteen million, five hundred five thousand, nine hundred thirteen".