645252387439 has 16 divisors (see below), whose sum is σ = 713694378240. Its totient is φ = 583315807800.

The previous prime is 645252387397. The next prime is 645252387463. The reversal of 645252387439 is 934783252546.

It is a happy number.

It is not a de Polignac number, because 645252387439 - 2³³ = 636662452847 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645252387239) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1115907 + ... + 1592404.

It is an arithmetic number, because the mean of its divisors is an integer number (44605898640).

Almost surely, 2^645252387439 is an apocalyptic number.

645252387439 is a deficient number, since it is larger than the sum of its proper divisors (68441990801).

645252387439 is a wasteful number, since it uses less digits than its factorization.

645252387439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2708523 (or 2708501 counting only the distinct ones).

The product of its digits is 43545600, while the sum is 58.

The spelling of 645252387439 in words is "six hundred forty-five billion, two hundred fifty-two million, three hundred eighty-seven thousand, four hundred thirty-nine".