666136633 has 4 divisors (see below), whose sum is σ = 668507508. Its totient is φ = 663765760.

The previous prime is 666136613. The next prime is 666136661. The reversal of 666136633 is 336631666.

It is a happy number.

666136633 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 376864569 + 289272064 = 19413^2 + 17008^2 .

It is a cyclic number.

It is not a de Polignac number, because 666136633 - 2²⁵ = 632582201 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666136613) 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, 1185016 + ... + 1185577.

It is an arithmetic number, because the mean of its divisors is an integer number (167126877).

Almost surely, 2^666136633 is an apocalyptic number.

It is an amenable number.

666136633 is a deficient number, since it is larger than the sum of its proper divisors (2370875).

666136633 is a wasteful number, since it uses less digits than its factorization.

666136633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2370874.

The product of its digits is 209952, while the sum is 40.

The square root of 666136633 is about 25809.6228759740. The cubic root of 666136633 is about 873.3488898258.

The spelling of 666136633 in words is "six hundred sixty-six million, one hundred thirty-six thousand, six hundred thirty-three".