161323403 has 4 divisors (see below), whose sum is σ = 168337488. Its totient is φ = 154309320.

The previous prime is 161323373. The next prime is 161323427. The reversal of 161323403 is 304323161.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161323403 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 7014061 = 161323403 / (1 + 6 + 1 + 3 + 2 + 3 + 4 + 0 + 3).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161323453) 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, 3507008 + ... + 3507053.

It is an arithmetic number, because the mean of its divisors is an integer number (42084372).

Almost surely, 2^161323403 is an apocalyptic number.

161323403 is a deficient number, since it is larger than the sum of its proper divisors (7014085).

161323403 is an equidigital number, since it uses as much as digits as its factorization.

161323403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7014084.

The product of its (nonzero) digits is 1296, while the sum is 23.

The square root of 161323403 is about 12701.3150106593. The cubic root of 161323403 is about 544.3761939328.

Adding to 161323403 its reverse (304323161), we get a palindrome (465646564).

The spelling of 161323403 in words is "one hundred sixty-one million, three hundred twenty-three thousand, four hundred three".