159681631 has 4 divisors (see below), whose sum is σ = 159924600. Its totient is φ = 159438664.

The previous prime is 159681623. The next prime is 159681637. The reversal of 159681631 is 136186951.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 136186951 = 3061 ⋅44491.

It is a cyclic number.

It is not a de Polignac number, because 159681631 - 2³ = 159681623 is a prime.

It is a super-2 number, since 2×159681631² = 50996446557640322, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (159681637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120496 + ... + 121813.

It is an arithmetic number, because the mean of its divisors is an integer number (39981150).

Almost surely, 2^159681631 is an apocalyptic number.

159681631 is a deficient number, since it is larger than the sum of its proper divisors (242969).

159681631 is an equidigital number, since it uses as much as digits as its factorization.

159681631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242968.

The product of its digits is 38880, while the sum is 40.

The square root of 159681631 is about 12636.5197344839. The cubic root of 159681631 is about 542.5232065504.

The spelling of 159681631 in words is "one hundred fifty-nine million, six hundred eighty-one thousand, six hundred thirty-one".