161491099 has 8 divisors (see below), whose sum is σ = 201339648. Its totient is φ = 125837160.

The previous prime is 161491093. The next prime is 161491103. The reversal of 161491099 is 990194161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 161491099 - 2⁵ = 161491067 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161491093) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1048567 + ... + 1048720.

It is an arithmetic number, because the mean of its divisors is an integer number (25167456).

Almost surely, 2^161491099 is an apocalyptic number.

161491099 is a deficient number, since it is larger than the sum of its proper divisors (39848549).

161491099 is a wasteful number, since it uses less digits than its factorization.

161491099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2097305.

The product of its (nonzero) digits is 17496, while the sum is 40.

The square root of 161491099 is about 12707.9148171523. The cubic root of 161491099 is about 544.5647553252.

The spelling of 161491099 in words is "one hundred sixty-one million, four hundred ninety-one thousand, ninety-nine".