1231611161 has 8 divisors (see below), whose sum is σ = 1346458464. Its totient is φ = 1117244320.

The previous prime is 1231611151. The next prime is 1231611169. The reversal of 1231611161 is 1611161321.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1231611161 - 2³⁰ = 157869337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1231611169) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 114740 + ... + 125013.

It is an arithmetic number, because the mean of its divisors is an integer number (168307308).

Almost surely, 2^1231611161 is an apocalyptic number.

1231611161 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1231611161 is a deficient number, since it is larger than the sum of its proper divisors (114847303).

1231611161 is a wasteful number, since it uses less digits than its factorization.

1231611161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 240231.

The product of its digits is 216, while the sum is 23.

The square root of 1231611161 is about 35094.3180728733. The cubic root of 1231611161 is about 1071.9088879017.

Adding to 1231611161 its reverse (1611161321), we get a palindrome (2842772482).

The spelling of 1231611161 in words is "one billion, two hundred thirty-one million, six hundred eleven thousand, one hundred sixty-one".