161999716 has 12 divisors (see below), whose sum is σ = 284094720. Its totient is φ = 80829800.

The previous prime is 161999711. The next prime is 161999743. The reversal of 161999716 is 617999161.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 161999716.

It is not an unprimeable number, because it can be changed into a prime (161999711) 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, 40360 + ... + 44191.

It is an arithmetic number, because the mean of its divisors is an integer number (23674560).

Almost surely, 2^161999716 is an apocalyptic number.

It is an amenable number.

161999716 is a deficient number, since it is larger than the sum of its proper divisors (122095004).

161999716 is a wasteful number, since it uses less digits than its factorization.

161999716 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85034 (or 85032 counting only the distinct ones).

The product of its digits is 183708, while the sum is 49.

The square root of 161999716 is about 12727.9109047793. The cubic root of 161999716 is about 545.1358592925.

The spelling of 161999716 in words is "one hundred sixty-one million, nine hundred ninety-nine thousand, seven hundred sixteen".