505111601661 has 4 divisors (see below), whose sum is σ = 673482135552. Its totient is φ = 336741067772.

The previous prime is 505111601647. The next prime is 505111601671. The reversal of 505111601661 is 166106111505.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 505111601661 - 2⁶ = 505111601597 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (505111601611) 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, 84185266941 + ... + 84185266946.

It is an arithmetic number, because the mean of its divisors is an integer number (168370533888).

Almost surely, 2^505111601661 is an apocalyptic number.

It is an amenable number.

505111601661 is a deficient number, since it is larger than the sum of its proper divisors (168370533891).

505111601661 is a wasteful number, since it uses less digits than its factorization.

505111601661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168370533890.

The product of its (nonzero) digits is 5400, while the sum is 33.

The spelling of 505111601661 in words is "five hundred five billion, one hundred eleven million, six hundred one thousand, six hundred sixty-one".