161841731 has 24 divisors (see below), whose sum is σ = 178375680. Its totient is φ = 146638800.

The previous prime is 161841707. The next prime is 161841733. The reversal of 161841731 is 137148161.

It is a de Polignac number, because none of the positive numbers 2^k-161841731 is a prime.

It is a super-2 number, since 2×161841731² = 52385491786152722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161841733) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1164260 + ... + 1164398.

It is an arithmetic number, because the mean of its divisors is an integer number (7432320).

Almost surely, 2^161841731 is an apocalyptic number.

161841731 is a deficient number, since it is larger than the sum of its proper divisors (16533949).

161841731 is a wasteful number, since it uses less digits than its factorization.

161841731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 287 (or 264 counting only the distinct ones).

The product of its digits is 4032, while the sum is 32.

The square root of 161841731 is about 12721.7031485568. The cubic root of 161841731 is about 544.9585929319.

Adding to 161841731 its reverse (137148161), we get a palindrome (298989892).

The spelling of 161841731 in words is "one hundred sixty-one million, eight hundred forty-one thousand, seven hundred thirty-one".