645195795191 has 4 divisors (see below), whose sum is σ = 654283059984. Its totient is φ = 636108530400.

The previous prime is 645195795187. The next prime is 645195795221. The reversal of 645195795191 is 191597591546.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 191597591546 = 2 ⋅95798795773.

It is a cyclic number.

It is not a de Polignac number, because 645195795191 - 2² = 645195795187 is a prime.

It is a super-2 number, since 2×645195795191² (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 (645195792191) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4543632290 + ... + 4543632431.

It is an arithmetic number, because the mean of its divisors is an integer number (163570764996).

Almost surely, 2^645195795191 is an apocalyptic number.

645195795191 is a deficient number, since it is larger than the sum of its proper divisors (9087264793).

645195795191 is an equidigital number, since it uses as much as digits as its factorization.

645195795191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9087264792.

The product of its digits is 15309000, while the sum is 62.

The spelling of 645195795191 in words is "six hundred forty-five billion, one hundred ninety-five million, seven hundred ninety-five thousand, one hundred ninety-one".