161538603 has 4 divisors (see below), whose sum is σ = 215384808. Its totient is φ = 107692400.

The previous prime is 161538557. The next prime is 161538623. The reversal of 161538603 is 306835161.

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 161538603 - 2⁸ = 161538347 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161538623) 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, 26923098 + ... + 26923103.

It is an arithmetic number, because the mean of its divisors is an integer number (53846202).

Almost surely, 2^161538603 is an apocalyptic number.

161538603 is a deficient number, since it is larger than the sum of its proper divisors (53846205).

161538603 is an equidigital number, since it uses as much as digits as its factorization.

161538603 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53846204.

The product of its (nonzero) digits is 12960, while the sum is 33.

The square root of 161538603 is about 12709.7837511108. The cubic root of 161538603 is about 544.6181462308.

The spelling of 161538603 in words is "one hundred sixty-one million, five hundred thirty-eight thousand, six hundred three".