2817725721 has 4 divisors (see below), whose sum is σ = 3756967632. Its totient is φ = 1878483812.

The previous prime is 2817725719. The next prime is 2817725731. The reversal of 2817725721 is 1275277182.

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.

It is a cyclic number.

It is not a de Polignac number, because 2817725721 - 2¹ = 2817725719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2817725731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 469620951 + ... + 469620956.

It is an arithmetic number, because the mean of its divisors is an integer number (939241908).

Almost surely, 2^2817725721 is an apocalyptic number.

It is an amenable number.

2817725721 is a deficient number, since it is larger than the sum of its proper divisors (939241911).

2817725721 is an equidigital number, since it uses as much as digits as its factorization.

2817725721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 939241910.

The product of its digits is 109760, while the sum is 42.

The square root of 2817725721 is about 53082.2542946322. The cubic root of 2817725721 is about 1412.4277409559.

The spelling of 2817725721 in words is "two billion, eight hundred seventeen million, seven hundred twenty-five thousand, seven hundred twenty-one".