161131213 has 2 divisors, whose sum is σ = 161131214. Its totient is φ = 161131212.

The previous prime is 161131147. The next prime is 161131231. The reversal of 161131213 is 312131161.

Together with next prime (161131231) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 81956809 + 79174404 = 9053^2 + 8898^2 .

It is a cyclic number.

It is not a de Polignac number, because 161131213 - 2²⁵ = 127576781 is a prime.

It is a plaindrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161135213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80565606 + 80565607.

It is an arithmetic number, because the mean of its divisors is an integer number (80565607).

Almost surely, 2^161131213 is an apocalyptic number.

It is an amenable number.

161131213 is a deficient number, since it is larger than the sum of its proper divisors (1).

161131213 is an equidigital number, since it uses as much as digits as its factorization.

161131213 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108, while the sum is 19.

The square root of 161131213 is about 12693.7470039386. The cubic root of 161131213 is about 544.1599301349.

Adding to 161131213 its reverse (312131161), we get a palindrome (473262374).

The spelling of 161131213 in words is "one hundred sixty-one million, one hundred thirty-one thousand, two hundred thirteen".