665636054238 has 48 divisors (see below), whose sum is σ = 1571320826160. Its totient is φ = 208826992512.

The previous prime is 665636054197. The next prime is 665636054257. The reversal of 665636054238 is 832450636566.

665636054238 is a `hidden beast` number, since 6 + 6 + 5 + 6 + 3 + 60 + 542 + 38 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 21310681 + ... + 21341892.

It is an arithmetic number, because the mean of its divisors is an integer number (32735850545).

Almost surely, 2^665636054238 is an apocalyptic number.

665636054238 is an abundant number, since it is smaller than the sum of its proper divisors (905684771922).

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

665636054238 is a wasteful number, since it uses less digits than its factorization.

665636054238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42652618 (or 42652595 counting only the distinct ones).

The product of its (nonzero) digits is 18662400, while the sum is 54.

The spelling of 665636054238 in words is "six hundred sixty-five billion, six hundred thirty-six million, fifty-four thousand, two hundred thirty-eight".