2491171565 has 32 divisors (see below), whose sum is σ = 3076254720. Its totient is φ = 1936224000.

The previous prime is 2491171549. The next prime is 2491171583. The reversal of 2491171565 is 5651711942.

It is a happy number.

2491171565 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 2491171565 - 2⁴ = 2491171549 is a prime.

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9192380 + ... + 9192650.

It is an arithmetic number, because the mean of its divisors is an integer number (96132960).

Almost surely, 2^2491171565 is an apocalyptic number.

It is an amenable number.

2491171565 is a deficient number, since it is larger than the sum of its proper divisors (585083155).

2491171565 is a wasteful number, since it uses less digits than its factorization.

2491171565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 653.

The product of its digits is 75600, while the sum is 41.

The square root of 2491171565 is about 49911.6375708111. The cubic root of 2491171565 is about 1355.6093200542.

The spelling of 2491171565 in words is "two billion, four hundred ninety-one million, one hundred seventy-one thousand, five hundred sixty-five".