645163776 has 108 divisors (see below), whose sum is σ = 1878268392. Its totient is φ = 212963328.

The previous prime is 645163751. The next prime is 645163801. The reversal of 645163776 is 677361546.

645163776 is a `hidden beast` number, since 6 + 4 + 5 + 1 + 637 + 7 + 6 = 666.

It is an interprime number because it is at equal distance from previous prime (645163751) and next prime (645163801).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 245220 + ... + 247836.

It is an arithmetic number, because the mean of its divisors is an integer number (17391374).

Almost surely, 2^645163776 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645163776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (939134196).

645163776 is an abundant number, since it is smaller than the sum of its proper divisors (1233104616).

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

645163776 is a wasteful number, since it uses less digits than its factorization.

645163776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2746 (or 2729 counting only the distinct ones).

The product of its digits is 635040, while the sum is 45.

The square root of 645163776 is about 25400.0743305999. The cubic root of 645163776 is about 864.0853825085.

The spelling of 645163776 in words is "six hundred forty-five million, one hundred sixty-three thousand, seven hundred seventy-six".