664797878 has 16 divisors (see below), whose sum is σ = 1052815920. Its totient is φ = 313963776.

The previous prime is 664797853. The next prime is 664797929. The reversal of 664797878 is 878797466.

664797878 is nontrivially palindromic in base 4.

It is a self number, because there is not a number n which added to its sum of digits gives 664797878.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13151 + ... + 38762.

It is an arithmetic number, because the mean of its divisors is an integer number (65800995).

Almost surely, 2^664797878 is an apocalyptic number.

664797878 is a deficient number, since it is larger than the sum of its proper divisors (388018042).

664797878 is a wasteful number, since it uses less digits than its factorization.

664797878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52271.

The product of its digits is 28449792, while the sum is 62.

The square root of 664797878 is about 25783.6746411368. The cubic root of 664797878 is about 872.7634321935.

The spelling of 664797878 in words is "six hundred sixty-four million, seven hundred ninety-seven thousand, eight hundred seventy-eight".