161815307 has 4 divisors (see below), whose sum is σ = 164868480. Its totient is φ = 158762136.

The previous prime is 161815279. The next prime is 161815309. The reversal of 161815307 is 703518161.

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

It is not a de Polignac number, because 161815307 - 2¹⁸ = 161553163 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161815309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1526507 + ... + 1526612.

It is an arithmetic number, because the mean of its divisors is an integer number (41217120).

Almost surely, 2^161815307 is an apocalyptic number.

161815307 is a deficient number, since it is larger than the sum of its proper divisors (3053173).

161815307 is an equidigital number, since it uses as much as digits as its factorization.

161815307 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3053172.

The product of its (nonzero) digits is 5040, while the sum is 32.

The square root of 161815307 is about 12720.6645659730. The cubic root of 161815307 is about 544.9289327416.

The spelling of 161815307 in words is "one hundred sixty-one million, eight hundred fifteen thousand, three hundred seven".