65633161661 has 4 divisors (see below), whose sum is σ = 67233970524. Its totient is φ = 64032352800.

The previous prime is 65633161639. The next prime is 65633161669. The reversal of 65633161661 is 16616133656.

It is a happy number.

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 26177298436 + 39455863225 = 161794^2 + 198635^2 .

It is a cyclic number.

It is not a de Polignac number, because 65633161661 - 2³⁴ = 48453292477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65633161669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 800404370 + ... + 800404451.

It is an arithmetic number, because the mean of its divisors is an integer number (16808492631).

Almost surely, 2^65633161661 is an apocalyptic number.

It is an amenable number.

65633161661 is a deficient number, since it is larger than the sum of its proper divisors (1600808863).

65633161661 is a wasteful number, since it uses less digits than its factorization.

65633161661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1600808862.

The product of its digits is 349920, while the sum is 44.

The spelling of 65633161661 in words is "sixty-five billion, six hundred thirty-three million, one hundred sixty-one thousand, six hundred sixty-one".