644875151 has 4 divisors (see below), whose sum is σ = 646632672. Its totient is φ = 643117632.

The previous prime is 644875111. The next prime is 644875159. The reversal of 644875151 is 151578446.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 151578446 = 2 ⋅75789223.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-644875151 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 644875099 and 644875108.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644875159) 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, 878210 + ... + 878943.

It is an arithmetic number, because the mean of its divisors is an integer number (161658168).

Almost surely, 2^644875151 is an apocalyptic number.

644875151 is a deficient number, since it is larger than the sum of its proper divisors (1757521).

644875151 is a wasteful number, since it uses less digits than its factorization.

644875151 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1757520.

The product of its digits is 134400, while the sum is 41.

The square root of 644875151 is about 25394.3921171585. The cubic root of 644875151 is about 863.9565088526.

The spelling of 644875151 in words is "six hundred forty-four million, eight hundred seventy-five thousand, one hundred fifty-one".