161394681 has 12 divisors (see below), whose sum is σ = 250326672. Its totient is φ = 92225448.

The previous prime is 161394661. The next prime is 161394697. The reversal of 161394681 is 186493161.

It is not a de Polignac number, because 161394681 - 2²¹ = 159297529 is a prime.

It is a super-2 number, since 2×161394681² = 52096486110183522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161394601) 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 11 ways as a sum of consecutive naturals, for example, 548815 + ... + 549108.

It is an arithmetic number, because the mean of its divisors is an integer number (20860556).

Almost surely, 2^161394681 is an apocalyptic number.

It is an amenable number.

161394681 is a deficient number, since it is larger than the sum of its proper divisors (88931991).

161394681 is a wasteful number, since it uses less digits than its factorization.

161394681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1097940 (or 1097933 counting only the distinct ones).

The product of its digits is 31104, while the sum is 39.

The square root of 161394681 is about 12704.1206307245. The cubic root of 161394681 is about 544.4563565799.

The spelling of 161394681 in words is "one hundred sixty-one million, three hundred ninety-four thousand, six hundred eighty-one".