167665661 has 2 divisors, whose sum is σ = 167665662. Its totient is φ = 167665660.

The previous prime is 167665657. The next prime is 167665681. The reversal of 167665661 is 166566761.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 161137636 + 6528025 = 12694^2 + 2555^2 .

It is a cyclic number.

It is not a de Polignac number, because 167665661 - 2² = 167665657 is a prime.

It is a super-2 number, since 2×167665661² = 56223547757133842, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (167665651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83832830 + 83832831.

It is an arithmetic number, because the mean of its divisors is an integer number (83832831).

Almost surely, 2^167665661 is an apocalyptic number.

It is an amenable number.

167665661 is a deficient number, since it is larger than the sum of its proper divisors (1).

167665661 is an equidigital number, since it uses as much as digits as its factorization.

167665661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 272160, while the sum is 44.

The square root of 167665661 is about 12948.5775666673. The cubic root of 167665661 is about 551.4185541129.

The spelling of 167665661 in words is "one hundred sixty-seven million, six hundred sixty-five thousand, six hundred sixty-one".