165917961 has 24 divisors (see below), whose sum is σ = 270466560. Its totient is φ = 97087200.

The previous prime is 165917957. The next prime is 165918031. The reversal of 165917961 is 169719561.

165917961 = T₂₁₉ + T₂₂₀ + ... + T₁₀₀₁.

165917961 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 165917961 - 2² = 165917957 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (165917461) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 26025 + ... + 31766.

It is an arithmetic number, because the mean of its divisors is an integer number (11269440).

Almost surely, 2^165917961 is an apocalyptic number.

165917961 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

165917961 is a deficient number, since it is larger than the sum of its proper divisors (104548599).

165917961 is a wasteful number, since it uses less digits than its factorization.

165917961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57837 (or 57834 counting only the distinct ones).

The product of its digits is 102060, while the sum is 45.

The square root of 165917961 is about 12880.9146026204. The cubic root of 165917961 is about 549.4959138936.

The spelling of 165917961 in words is "one hundred sixty-five million, nine hundred seventeen thousand, nine hundred sixty-one".