161312279769 has 27 divisors (see below), whose sum is σ = 235994065567. Its totient is φ = 106179970416.

The previous prime is 161312279749. The next prime is 161312279801. The reversal of 161312279769 is 967972213161.

The square root of 161312279769 is 401637.

It is a perfect power (a square), and thus also a powerful number.

161312279769 is a `hidden beast` number, since 1 + 613 + 12 + 2 + 7 + 9 + 7 + 6 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 100790375625 + 60521904144 = 317475^2 + 246012^2 .

It is a de Polignac number, because none of the positive numbers 2^k-161312279769 is a prime.

It is a super-2 number, since 2×161312279769² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161312279749) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 100006807 + ... + 100008419.

Almost surely, 2^161312279769 is an apocalyptic number.

161312279769 is the 401637-th square number.

161312279769 is the 200819-th centered octagonal number.

It is an amenable number.

161312279769 is a deficient number, since it is larger than the sum of its proper divisors (74681785798).

161312279769 is an frugal number, since it uses more digits than its factorization.

161312279769 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3398 (or 1699 counting only the distinct ones).

The product of its digits is 1714608, while the sum is 54.

The spelling of 161312279769 in words is "one hundred sixty-one billion, three hundred twelve million, two hundred seventy-nine thousand, seven hundred sixty-nine".