161776771 has 12 divisors (see below), whose sum is σ = 175991832. Its totient is φ = 148639296.

The previous prime is 161776763. The next prime is 161776781. The reversal of 161776771 is 177677161.

It is not a de Polignac number, because 161776771 - 2³ = 161776763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161776721) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 36255 + ... + 40471.

It is an arithmetic number, because the mean of its divisors is an integer number (14665986).

Almost surely, 2^161776771 is an apocalyptic number.

161776771 is a deficient number, since it is larger than the sum of its proper divisors (14215061).

161776771 is a wasteful number, since it uses less digits than its factorization.

161776771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4470 (or 4457 counting only the distinct ones).

The product of its digits is 86436, while the sum is 43.

The square root of 161776771 is about 12719.1497750439. The cubic root of 161776771 is about 544.8856713861.

The spelling of 161776771 in words is "one hundred sixty-one million, seven hundred seventy-six thousand, seven hundred seventy-one".