645818634 has 96 divisors (see below), whose sum is σ = 1501403904. Its totient is φ = 200309760.

The previous prime is 645818611. The next prime is 645818639. The reversal of 645818634 is 436818546.

645818634 is a `hidden beast` number, since 6 + 4 + 5 + 8 + 1 + 8 + 634 = 666.

645818634 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 645818634.

It is not an unprimeable number, because it can be changed into a prime (645818639) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1491282 + ... + 1491714.

It is an arithmetic number, because the mean of its divisors is an integer number (15639624).

Almost surely, 2^645818634 is an apocalyptic number.

645818634 is an abundant number, since it is smaller than the sum of its proper divisors (855585270).

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

645818634 is a wasteful number, since it uses less digits than its factorization.

645818634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 572 (or 569 counting only the distinct ones).

The product of its digits is 552960, while the sum is 45.

The square root of 645818634 is about 25412.9619289055. The cubic root of 645818634 is about 864.3776400212.

The spelling of 645818634 in words is "six hundred forty-five million, eight hundred eighteen thousand, six hundred thirty-four".