161131556141 has 4 divisors (see below), whose sum is σ = 161773514784. Its totient is φ = 160489597500.

The previous prime is 161131556099. The next prime is 161131556171. The reversal of 161131556141 is 141655131161.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161131556141 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 (161131556171) 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, 320978945 + ... + 320979446.

It is an arithmetic number, because the mean of its divisors is an integer number (40443378696).

Almost surely, 2^161131556141 is an apocalyptic number.

It is an amenable number.

161131556141 is a deficient number, since it is larger than the sum of its proper divisors (641958643).

161131556141 is an equidigital number, since it uses as much as digits as its factorization.

161131556141 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 641958642.

The product of its digits is 10800, while the sum is 35.

The spelling of 161131556141 in words is "one hundred sixty-one billion, one hundred thirty-one million, five hundred fifty-six thousand, one hundred forty-one".