165786611657 has 4 divisors (see below), whose sum is σ = 167092018176. Its totient is φ = 164481205140.

The previous prime is 165786611611. The next prime is 165786611663. The reversal of 165786611657 is 756116687561.

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 165786611657 - 2⁸ = 165786611401 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 165786611596 and 165786611605.

It is not an unprimeable number, because it can be changed into a prime (165786611357) 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, 652703069 + ... + 652703322.

It is an arithmetic number, because the mean of its divisors is an integer number (41773004544).

Almost surely, 2^165786611657 is an apocalyptic number.

It is an amenable number.

165786611657 is a deficient number, since it is larger than the sum of its proper divisors (1305406519).

165786611657 is a wasteful number, since it uses less digits than its factorization.

165786611657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1305406518.

The product of its digits is 12700800, while the sum is 59.

The spelling of 165786611657 in words is "one hundred sixty-five billion, seven hundred eighty-six million, six hundred eleven thousand, six hundred fifty-seven".