161100503 has 4 divisors (see below), whose sum is σ = 163831080. Its totient is φ = 158369928.

The previous prime is 161100469. The next prime is 161100529. The reversal of 161100503 is 305001161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 305001161 = 71 ⋅4295791.

It is a cyclic number.

It is not a de Polignac number, because 161100503 - 2¹⁰ = 161099479 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161100103) 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, 1365200 + ... + 1365317.

It is an arithmetic number, because the mean of its divisors is an integer number (40957770).

Almost surely, 2^161100503 is an apocalyptic number.

161100503 is a deficient number, since it is larger than the sum of its proper divisors (2730577).

161100503 is an equidigital number, since it uses as much as digits as its factorization.

161100503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2730576.

The product of its (nonzero) digits is 90, while the sum is 17.

The square root of 161100503 is about 12692.5372955922. The cubic root of 161100503 is about 544.1253574556.

Adding to 161100503 its reverse (305001161), we get a palindrome (466101664).

The spelling of 161100503 in words is "one hundred sixty-one million, one hundred thousand, five hundred three".