161987199 has 16 divisors (see below), whose sum is σ = 238460544. Its totient is φ = 96989600.

The previous prime is 161987197. The next prime is 161987249. The reversal of 161987199 is 991789161.

It is a cyclic number.

It is not a de Polignac number, because 161987199 - 2¹ = 161987197 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161987197) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26832 + ... + 32309.

It is an arithmetic number, because the mean of its divisors is an integer number (14903784).

Almost surely, 2^161987199 is an apocalyptic number.

161987199 is a deficient number, since it is larger than the sum of its proper divisors (76473345).

161987199 is a wasteful number, since it uses less digits than its factorization.

161987199 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59238.

The product of its digits is 244944, while the sum is 51.

The square root of 161987199 is about 12727.4191806509. The cubic root of 161987199 is about 545.1218188537.

The spelling of 161987199 in words is "one hundred sixty-one million, nine hundred eighty-seven thousand, one hundred ninety-nine".