645891754536 has 96 divisors (see below), whose sum is σ = 1999383609600. Its totient is φ = 184522515840.

The previous prime is 645891754517. The next prime is 645891754553. The reversal of 645891754536 is 635457198546.

It is a happy number.

645891754536 is a `hidden beast` number, since 6 + 4 + 5 + 8 + 9 + 175 + 453 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5627806 + ... + 5741426.

It is an arithmetic number, because the mean of its divisors is an integer number (20826912600).

Almost surely, 2^645891754536 is an apocalyptic number.

It is an amenable number.

645891754536 is an abundant number, since it is smaller than the sum of its proper divisors (1353491855064).

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

645891754536 is a wasteful number, since it uses less digits than its factorization.

645891754536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124919 (or 124912 counting only the distinct ones).

The product of its digits is 108864000, while the sum is 63.

The spelling of 645891754536 in words is "six hundred forty-five billion, eight hundred ninety-one million, seven hundred fifty-four thousand, five hundred thirty-six".