646882015878 has 24 divisors (see below), whose sum is σ = 1601803087248. Its totient is φ = 184823433072.

The previous prime is 646882015877. The next prime is 646882015883. The reversal of 646882015878 is 878510288646.

646882015878 is a `hidden beast` number, since 6 + 46 + 8 + 8 + 2 + 0 + 1 + 587 + 8 = 666.

It is a super-2 number, since 2×646882015878² (a number of 24 digits) contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646882015877) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 2566992001 + ... + 2566992252.

It is an arithmetic number, because the mean of its divisors is an integer number (66741795302).

Almost surely, 2^646882015878 is an apocalyptic number.

646882015878 is an abundant number, since it is smaller than the sum of its proper divisors (954921071370).

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

646882015878 is a wasteful number, since it uses less digits than its factorization.

646882015878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5133984268 (or 5133984265 counting only the distinct ones).

The product of its (nonzero) digits is 41287680, while the sum is 63.

The spelling of 646882015878 in words is "six hundred forty-six billion, eight hundred eighty-two million, fifteen thousand, eight hundred seventy-eight".