161235345921 has 64 divisors (see below), whose sum is σ = 253262370816. Its totient is φ = 90294681600.

The previous prime is 161235345889. The next prime is 161235346007. The reversal of 161235345921 is 129543532161.

It is not a de Polignac number, because 161235345921 - 2⁵ = 161235345889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161235345421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 30436345 + ... + 30441641.

It is an arithmetic number, because the mean of its divisors is an integer number (3957224544).

Almost surely, 2^161235345921 is an apocalyptic number.

It is an amenable number.

161235345921 is a deficient number, since it is larger than the sum of its proper divisors (92027024895).

161235345921 is a wasteful number, since it uses less digits than its factorization.

161235345921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6842.

The product of its digits is 194400, while the sum is 42.

The spelling of 161235345921 in words is "one hundred sixty-one billion, two hundred thirty-five million, three hundred forty-five thousand, nine hundred twenty-one".