165117661 has 2 divisors, whose sum is σ = 165117662. Its totient is φ = 165117660.

The previous prime is 165117647. The next prime is 165117679. The reversal of 165117661 is 166711561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 161137636 + 3980025 = 12694^2 + 1995^2 .

It is a cyclic number.

It is not a de Polignac number, because 165117661 - 2⁵ = 165117629 is a prime.

It is a super-2 number, since 2×165117661² = 54527683948221842, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165117061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82558830 + 82558831.

It is an arithmetic number, because the mean of its divisors is an integer number (82558831).

Almost surely, 2^165117661 is an apocalyptic number.

It is an amenable number.

165117661 is a deficient number, since it is larger than the sum of its proper divisors (1).

165117661 is an equidigital number, since it uses as much as digits as its factorization.

165117661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7560, while the sum is 34.

The square root of 165117661 is about 12849.8117106828. The cubic root of 165117661 is about 548.6109975637.

The spelling of 165117661 in words is "one hundred sixty-five million, one hundred seventeen thousand, six hundred sixty-one".