1211210131 has 4 divisors (see below), whose sum is σ = 1218641032. Its totient is φ = 1203779232.

The previous prime is 1211210129. The next prime is 1211210137. The reversal of 1211210131 is 1310121121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1310121121 = 3929 ⋅333449.

It is a cyclic number.

It is not a de Polignac number, because 1211210131 - 2¹ = 1211210129 is a prime.

It is a super-2 number, since 2×1211210131² = 2934059962874074322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211210137) 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, 3715206 + ... + 3715531.

It is an arithmetic number, because the mean of its divisors is an integer number (304660258).

Almost surely, 2^1211210131 is an apocalyptic number.

1211210131 is a deficient number, since it is larger than the sum of its proper divisors (7430901).

1211210131 is an equidigital number, since it uses as much as digits as its factorization.

1211210131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7430900.

The product of its (nonzero) digits is 12, while the sum is 13.

The square root of 1211210131 is about 34802.4443250758. Note that the first 3 decimals coincide. The cubic root of 1211210131 is about 1065.9573576077.

Adding to 1211210131 its reverse (1310121121), we get a palindrome (2521331252).

The spelling of 1211210131 in words is "one billion, two hundred eleven million, two hundred ten thousand, one hundred thirty-one".