664786978254 has 48 divisors (see below), whose sum is σ = 1699240458240. Its totient is φ = 183812066640.

The previous prime is 664786978243. The next prime is 664786978279. The reversal of 664786978254 is 452879687466.

664786978254 is a `hidden beast` number, since 6 + 6 + 478 + 69 + 78 + 25 + 4 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 85094274 + ... + 85102085.

It is an arithmetic number, because the mean of its divisors is an integer number (35400842880).

Almost surely, 2^664786978254 is an apocalyptic number.

664786978254 is an abundant number, since it is smaller than the sum of its proper divisors (1034453479986).

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

664786978254 is a wasteful number, since it uses less digits than its factorization.

664786978254 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170196405 (or 170196402 counting only the distinct ones).

The product of its digits is 975421440, while the sum is 72.

The spelling of 664786978254 in words is "six hundred sixty-four billion, seven hundred eighty-six million, nine hundred seventy-eight thousand, two hundred fifty-four".