665561636236 has 12 divisors (see below), whose sum is σ = 1331123272528. Its totient is φ = 285240701232.

The previous prime is 665561636227. The next prime is 665561636237. The reversal of 665561636236 is 632636165566.

665561636236 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

665561636236 is an admirable number.

It is a hoax number, since the sum of its digits (55) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (665561636237) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11885029191 + ... + 11885029246.

Almost surely, 2^665561636236 is an apocalyptic number.

It is an amenable number.

665561636236 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

665561636236 is a wasteful number, since it uses less digits than its factorization.

665561636236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23770058448 (or 23770058446 counting only the distinct ones).

The product of its digits is 20995200, while the sum is 55.

The spelling of 665561636236 in words is "six hundred sixty-five billion, five hundred sixty-one million, six hundred thirty-six thousand, two hundred thirty-six".