161961959 has 4 divisors (see below), whose sum is σ = 162076416. Its totient is φ = 161847504.

The previous prime is 161961923. The next prime is 161961971. The reversal of 161961959 is 959169161.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161961959 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161961979) 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, 55079 + ... + 57944.

It is an arithmetic number, because the mean of its divisors is an integer number (40519104).

Almost surely, 2^161961959 is an apocalyptic number.

161961959 is a deficient number, since it is larger than the sum of its proper divisors (114457).

161961959 is a wasteful number, since it uses less digits than its factorization.

161961959 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114456.

The product of its digits is 131220, while the sum is 47.

The square root of 161961959 is about 12726.4275820043. The cubic root of 161961959 is about 545.0935047041.

The spelling of 161961959 in words is "one hundred sixty-one million, nine hundred sixty-one thousand, nine hundred fifty-nine".