645936777759 has 64 divisors (see below), whose sum is σ = 1088961269760. Its totient is φ = 333463553280.

The previous prime is 645936777737. The next prime is 645936777793. The reversal of 645936777759 is 957777639546.

It is not a de Polignac number, because 645936777759 - 2⁷ = 645936777631 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645936777259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2019499 + ... + 2317379.

It is an arithmetic number, because the mean of its divisors is an integer number (17015019840).

Almost surely, 2^645936777759 is an apocalyptic number.

645936777759 is a deficient number, since it is larger than the sum of its proper divisors (443024492001).

645936777759 is a wasteful number, since it uses less digits than its factorization.

645936777759 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 297977 (or 297951 counting only the distinct ones).

The product of its digits is 2100394800, while the sum is 75.

The spelling of 645936777759 in words is "six hundred forty-five billion, nine hundred thirty-six million, seven hundred seventy-seven thousand, seven hundred fifty-nine".