645313576878 has 48 divisors (see below), whose sum is σ = 1420331024736. Its totient is φ = 211707095040.

The previous prime is 645313576877. The next prime is 645313576879. The reversal of 645313576878 is 878675313546.

It is a happy number.

645313576878 is a `hidden beast` number, since 6 + 4 + 53 + 1 + 3 + 576 + 8 + 7 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (645313576877) and next prime (645313576879).

It is a super-2 number, since 2×645313576878² (a number of 24 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645313576877) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 299850 + ... + 1174962.

It is an arithmetic number, because the mean of its divisors is an integer number (29590229682).

Almost surely, 2^645313576878 is an apocalyptic number.

645313576878 is an abundant number, since it is smaller than the sum of its proper divisors (775017447858).

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

645313576878 is a wasteful number, since it uses less digits than its factorization.

645313576878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 875769 (or 875766 counting only the distinct ones).

The product of its digits is 101606400, while the sum is 63.

The spelling of 645313576878 in words is "six hundred forty-five billion, three hundred thirteen million, five hundred seventy-six thousand, eight hundred seventy-eight".