161157499 has 4 divisors (see below), whose sum is σ = 166356160. Its totient is φ = 155958840.

The previous prime is 161157473. The next prime is 161157523. The reversal of 161157499 is 994751161.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 994751161 = 827 ⋅1202843.

It is a cyclic number.

It is not a de Polignac number, because 161157499 - 2⁹ = 161156987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161157419) 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, 2599284 + ... + 2599345.

It is an arithmetic number, because the mean of its divisors is an integer number (41589040).

Almost surely, 2^161157499 is an apocalyptic number.

161157499 is a deficient number, since it is larger than the sum of its proper divisors (5198661).

161157499 is an equidigital number, since it uses as much as digits as its factorization.

161157499 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5198660.

The product of its digits is 68040, while the sum is 43.

The square root of 161157499 is about 12694.7823533923. The cubic root of 161157499 is about 544.1895188779.

The spelling of 161157499 in words is "one hundred sixty-one million, one hundred fifty-seven thousand, four hundred ninety-nine".