634334387191 has 4 divisors (see below), whose sum is σ = 635296959000. Its totient is φ = 633371815384.

The previous prime is 634334387189. The next prime is 634334387209. The reversal of 634334387191 is 191783433436.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 634334387191 - 2¹ = 634334387189 is a prime.

It is a super-2 number, since 2×634334387191² (a number of 24 digits) 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 (634334387161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 481284916 + ... + 481286233.

It is an arithmetic number, because the mean of its divisors is an integer number (158824239750).

Almost surely, 2^634334387191 is an apocalyptic number.

634334387191 is a deficient number, since it is larger than the sum of its proper divisors (962571809).

634334387191 is an equidigital number, since it uses as much as digits as its factorization.

634334387191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 962571808.

The product of its digits is 3919104, while the sum is 52.

The spelling of 634334387191 in words is "six hundred thirty-four billion, three hundred thirty-four million, three hundred eighty-seven thousand, one hundred ninety-one".