645365736630 has 160 divisors (see below), whose sum is σ = 1842257118240. Its totient is φ = 161545466880.

The previous prime is 645365736601. The next prime is 645365736667. The reversal of 645365736630 is 36637563546.

645365736630 is a `hidden beast` number, since 6 + 4 + 5 + 3 + 6 + 573 + 6 + 63 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

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 79 ways as a sum of consecutive naturals, for example, 5157000 + ... + 5280660.

It is an arithmetic number, because the mean of its divisors is an integer number (11514106989).

Almost surely, 2^645365736630 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645365736630, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (921128559120).

645365736630 is an abundant number, since it is smaller than the sum of its proper divisors (1196891381610).

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

645365736630 is a wasteful number, since it uses less digits than its factorization.

645365736630 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124076 (or 124067 counting only the distinct ones).

The product of its (nonzero) digits is 24494400, while the sum is 54.

The spelling of 645365736630 in words is "six hundred forty-five billion, three hundred sixty-five million, seven hundred thirty-six thousand, six hundred thirty".