161223507 has 16 divisors (see below), whose sum is σ = 242417280. Its totient is φ = 105876936.

The previous prime is 161223481. The next prime is 161223511. The reversal of 161223507 is 705322161.

It is a happy number.

It is not a de Polignac number, because 161223507 - 2⁶ = 161223443 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (161223547) 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 15 ways as a sum of consecutive naturals, for example, 42753 + ... + 46370.

It is an arithmetic number, because the mean of its divisors is an integer number (15151080).

Almost surely, 2^161223507 is an apocalyptic number.

161223507 is a deficient number, since it is larger than the sum of its proper divisors (81193773).

161223507 is an equidigital number, since it uses as much as digits as its factorization.

161223507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89199 (or 89193 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 27.

The square root of 161223507 is about 12697.3818954933. The cubic root of 161223507 is about 544.2638063687.

Adding to 161223507 its reverse (705322161), we get a palindrome (866545668).

The spelling of 161223507 in words is "one hundred sixty-one million, two hundred twenty-three thousand, five hundred seven".