644374942195 has 8 divisors (see below), whose sum is σ = 773255564640. Its totient is φ = 515496197760.

The previous prime is 644374942193. The next prime is 644374942199. The reversal of 644374942195 is 591249473446.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 644374942195 - 2¹ = 644374942193 is a prime.

It is a super-2 number, since 2×644374942195² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (644374942193) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 448555 + ... + 1220635.

It is an arithmetic number, because the mean of its divisors is an integer number (96656945580).

Almost surely, 2^644374942195 is an apocalyptic number.

644374942195 is a deficient number, since it is larger than the sum of its proper divisors (128880622445).

644374942195 is a wasteful number, since it uses less digits than its factorization.

644374942195 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 939005.

The product of its digits is 26127360, while the sum is 58.

The spelling of 644374942195 in words is "six hundred forty-four billion, three hundred seventy-four million, nine hundred forty-two thousand, one hundred ninety-five".