161531340603 has 4 divisors (see below), whose sum is σ = 215375120808. Its totient is φ = 107687560400.

The previous prime is 161531340601. The next prime is 161531340631. The reversal of 161531340603 is 306043135161.

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 161531340603 - 2¹ = 161531340601 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161531340601) 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, 26921890098 + ... + 26921890103.

It is an arithmetic number, because the mean of its divisors is an integer number (53843780202).

Almost surely, 2^161531340603 is an apocalyptic number.

161531340603 is a deficient number, since it is larger than the sum of its proper divisors (53843780205).

161531340603 is an equidigital number, since it uses as much as digits as its factorization.

161531340603 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53843780204.

The product of its (nonzero) digits is 19440, while the sum is 33.

Adding to 161531340603 its reverse (306043135161), we get a palindrome (467574475764).

The spelling of 161531340603 in words is "one hundred sixty-one billion, five hundred thirty-one million, three hundred forty thousand, six hundred three".