642779937868 has 48 divisors (see below), whose sum is σ = 1159507651680. Its totient is φ = 311654214144.

The previous prime is 642779937827. The next prime is 642779937869. The reversal of 642779937868 is 868739977246.

642779937868 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 642779937794 and 642779937803.

It is not an unprimeable number, because it can be changed into a prime (642779937869) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6602755 + ... + 6699397.

It is an arithmetic number, because the mean of its divisors is an integer number (24156409410).

Almost surely, 2^642779937868 is an apocalyptic number.

It is an amenable number.

642779937868 is a deficient number, since it is larger than the sum of its proper divisors (516727713812).

642779937868 is a wasteful number, since it uses less digits than its factorization.

642779937868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97066 (or 97064 counting only the distinct ones).

The product of its digits is 1536288768, while the sum is 76.

The spelling of 642779937868 in words is "six hundred forty-two billion, seven hundred seventy-nine million, nine hundred thirty-seven thousand, eight hundred sixty-eight".