161061956771 has 4 divisors (see below), whose sum is σ = 161063094000. Its totient is φ = 161060819544.

The previous prime is 161061956719. The next prime is 161061956773. The reversal of 161061956771 is 177659160161.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161061956771 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161061956773) 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, 319916 + ... + 651513.

It is an arithmetic number, because the mean of its divisors is an integer number (40265773500).

Almost surely, 2^161061956771 is an apocalyptic number.

161061956771 is a deficient number, since it is larger than the sum of its proper divisors (1137229).

161061956771 is an equidigital number, since it uses as much as digits as its factorization.

161061956771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1137228.

The product of its (nonzero) digits is 476280, while the sum is 50.

The spelling of 161061956771 in words is "one hundred sixty-one billion, sixty-one million, nine hundred fifty-six thousand, seven hundred seventy-one".