161156020781 has 8 divisors (see below), whose sum is σ = 186927240000. Its totient is φ = 136072034208.

The previous prime is 161156020771. The next prime is 161156020811. The reversal of 161156020781 is 187020651161.

161156020781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161156020781 is a prime.

It is a super-2 number, since 2×161156020781² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161156020771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 171807656 + ... + 171808593.

It is an arithmetic number, because the mean of its divisors is an integer number (23365905000).

Almost surely, 2^161156020781 is an apocalyptic number.

It is an amenable number.

161156020781 is a deficient number, since it is larger than the sum of its proper divisors (25771219219).

161156020781 is an equidigital number, since it uses as much as digits as its factorization.

161156020781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 343616323.

The product of its (nonzero) digits is 20160, while the sum is 38.

The spelling of 161156020781 in words is "one hundred sixty-one billion, one hundred fifty-six million, twenty thousand, seven hundred eighty-one".