861791619 has 16 divisors (see below), whose sum is σ = 1238532512. Its totient is φ = 529867008.

The previous prime is 861791617. The next prime is 861791639. The reversal of 861791619 is 916197168.

It is not a de Polignac number, because 861791619 - 2¹ = 861791617 is a prime.

It is a super-2 number, since 2×861791619² = 1485369589157282322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (861791611) 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 15 ways as a sum of consecutive naturals, for example, 38199 + ... + 56415.

It is an arithmetic number, because the mean of its divisors is an integer number (77408282).

Almost surely, 2^861791619 is an apocalyptic number.

861791619 is a deficient number, since it is larger than the sum of its proper divisors (376740893).

861791619 is a wasteful number, since it uses less digits than its factorization.

861791619 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19446.

The product of its digits is 163296, while the sum is 48.

The square root of 861791619 is about 29356.2875547982. The cubic root of 861791619 is about 951.6284605035.

The spelling of 861791619 in words is "eight hundred sixty-one million, seven hundred ninety-one thousand, six hundred nineteen".