161556099 has 4 divisors (see below), whose sum is σ = 215408136. Its totient is φ = 107704064.

The previous prime is 161556089. The next prime is 161556167. The reversal of 161556099 is 990655161.

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

It is a cyclic number.

It is not a de Polignac number, because 161556099 - 2⁹ = 161555587 is a prime.

It is a super-2 number, since 2×161556099² = 52200746248195602, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 161556099.

It is not an unprimeable number, because it can be changed into a prime (161556079) 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 3 ways as a sum of consecutive naturals, for example, 26926014 + ... + 26926019.

It is an arithmetic number, because the mean of its divisors is an integer number (53852034).

Almost surely, 2^161556099 is an apocalyptic number.

161556099 is a deficient number, since it is larger than the sum of its proper divisors (53852037).

161556099 is an equidigital number, since it uses as much as digits as its factorization.

161556099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53852036.

The product of its (nonzero) digits is 72900, while the sum is 42.

The square root of 161556099 is about 12710.4720211328. The cubic root of 161556099 is about 544.6378077748.

The spelling of 161556099 in words is "one hundred sixty-one million, five hundred fifty-six thousand, ninety-nine".