161255503 has 4 divisors (see below), whose sum is σ = 161829648. Its totient is φ = 160681360.

The previous prime is 161255491. The next prime is 161255593. The reversal of 161255503 is 305552161.

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 161255503 - 2¹³ = 161247311 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 (161255593) 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, 286651 + ... + 287212.

It is an arithmetic number, because the mean of its divisors is an integer number (40457412).

Almost surely, 2^161255503 is an apocalyptic number.

161255503 is a deficient number, since it is larger than the sum of its proper divisors (574145).

161255503 is an equidigital number, since it uses as much as digits as its factorization.

161255503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 574144.

The product of its (nonzero) digits is 4500, while the sum is 28.

The square root of 161255503 is about 12698.6417777651. The cubic root of 161255503 is about 544.2998083827.

The spelling of 161255503 in words is "one hundred sixty-one million, two hundred fifty-five thousand, five hundred three".