1211312131 has 2 divisors, whose sum is σ = 1211312132. Its totient is φ = 1211312130.

The previous prime is 1211312099. The next prime is 1211312143. The reversal of 1211312131 is 1312131121.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1211312131 - 2⁵ = 1211312099 is a prime.

It is a super-2 number, since 2×1211312131² = 2934554157415522322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1211312231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605656065 + 605656066.

It is an arithmetic number, because the mean of its divisors is an integer number (605656066).

Almost surely, 2^1211312131 is an apocalyptic number.

1211312131 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211312131 is an equidigital number, since it uses as much as digits as its factorization.

1211312131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36, while the sum is 16.

The square root of 1211312131 is about 34803.9097085371. The cubic root of 1211312131 is about 1065.9872793627.

Adding to 1211312131 its reverse (1312131121), we get a palindrome (2523443252).

It can be divided in two parts, 121 and 1312131, that multiplied together give a palindrome (158767851).

The spelling of 1211312131 in words is "one billion, two hundred eleven million, three hundred twelve thousand, one hundred thirty-one".