161556332811 has 8 divisors (see below), whose sum is σ = 219059434560. Its totient is φ = 105878726472.

The previous prime is 161556332807. The next prime is 161556332813. The reversal of 161556332811 is 118233655161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 161556332811 - 2² = 161556332807 is a prime.

It is a super-2 number, since 2×161556332811² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161556332813) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 456373645 + ... + 456373998.

It is an arithmetic number, because the mean of its divisors is an integer number (27382429320).

Almost surely, 2^161556332811 is an apocalyptic number.

161556332811 is a deficient number, since it is larger than the sum of its proper divisors (57503101749).

161556332811 is an equidigital number, since it uses as much as digits as its factorization.

161556332811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 912747705.

The product of its digits is 129600, while the sum is 42.

Adding to 161556332811 its reverse (118233655161), we get a palindrome (279789987972).

The spelling of 161556332811 in words is "one hundred sixty-one billion, five hundred fifty-six million, three hundred thirty-two thousand, eight hundred eleven".