161893881243 has 12 divisors (see below), whose sum is σ = 233851863960. Its totient is φ = 107926878816.

The previous prime is 161893881239. The next prime is 161893881257. The reversal of 161893881243 is 342188398161.

161893881243 is a `hidden beast` number, since 1 + 6 + 18 + 9 + 388 + 1 + 243 = 666.

It is not a de Polignac number, because 161893881243 - 2² = 161893881239 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 161893881243.

It is not an unprimeable number, because it can be changed into a prime (161893881283) 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, 299503 + ... + 643031.

It is an arithmetic number, because the mean of its divisors is an integer number (19487655330).

Almost surely, 2^161893881243 is an apocalyptic number.

161893881243 is a deficient number, since it is larger than the sum of its proper divisors (71957982717).

161893881243 is a wasteful number, since it uses less digits than its factorization.

161893881243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 395898 (or 395895 counting only the distinct ones).

The product of its digits is 1990656, while the sum is 54.

The spelling of 161893881243 in words is "one hundred sixty-one billion, eight hundred ninety-three million, eight hundred eighty-one thousand, two hundred forty-three".