645786720534 has 32 divisors (see below), whose sum is σ = 1307207341440. Its totient is φ = 212656879232.

The previous prime is 645786720511. The next prime is 645786720619. The reversal of 645786720534 is 435027687546.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16707022 + ... + 16745630.

It is an arithmetic number, because the mean of its divisors is an integer number (40850229420).

Almost surely, 2^645786720534 is an apocalyptic number.

645786720534 is an abundant number, since it is smaller than the sum of its proper divisors (661420620906).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

645786720534 is a wasteful number, since it uses less digits than its factorization.

645786720534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72284.

The product of its (nonzero) digits is 33868800, while the sum is 57.

The spelling of 645786720534 in words is "six hundred forty-five billion, seven hundred eighty-six million, seven hundred twenty thousand, five hundred thirty-four".