2170721613 has 4 divisors (see below), whose sum is σ = 2894295488. Its totient is φ = 1447147740.

The previous prime is 2170721591. The next prime is 2170721627. The reversal of 2170721613 is 3161270712.

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 not a de Polignac number, because 2170721613 - 2²⁵ = 2137167181 is a prime.

It is a super-2 number, since 2×2170721613² = 9424064642290643538, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2170721713) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 361786933 + ... + 361786938.

It is an arithmetic number, because the mean of its divisors is an integer number (723573872).

Almost surely, 2^2170721613 is an apocalyptic number.

It is an amenable number.

2170721613 is a deficient number, since it is larger than the sum of its proper divisors (723573875).

2170721613 is an equidigital number, since it uses as much as digits as its factorization.

2170721613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 723573874.

The product of its (nonzero) digits is 3528, while the sum is 30.

The square root of 2170721613 is about 46591.0035629197. The cubic root of 2170721613 is about 1294.7960826387.

The spelling of 2170721613 in words is "two billion, one hundred seventy million, seven hundred twenty-one thousand, six hundred thirteen".