1231016161 has 4 divisors (see below), whose sum is σ = 1237265172. Its totient is φ = 1224767152.

The previous prime is 1231016147. The next prime is 1231016177. The reversal of 1231016161 is 1616101321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1616101321 = 179 ⋅9028499.

It can be written as a sum of positive squares in 2 ways, for example, as 771728400 + 459287761 = 27780^2 + 21431^2 .

It is a cyclic number.

It is not a de Polignac number, because 1231016161 - 2¹⁵ = 1230983393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1231016861) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3124210 + ... + 3124603.

It is an arithmetic number, because the mean of its divisors is an integer number (309316293).

Almost surely, 2^1231016161 is an apocalyptic number.

It is an amenable number.

1231016161 is a deficient number, since it is larger than the sum of its proper divisors (6249011).

1231016161 is an equidigital number, since it uses as much as digits as its factorization.

1231016161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6249010.

The product of its (nonzero) digits is 216, while the sum is 22.

The square root of 1231016161 is about 35085.8398930395. The cubic root of 1231016161 is about 1071.7362445269.

Adding to 1231016161 its reverse (1616101321), we get a palindrome (2847117482).

The spelling of 1231016161 in words is "one billion, two hundred thirty-one million, sixteen thousand, one hundred sixty-one".