11311212131 has 4 divisors (see below), whose sum is σ = 11312283192. Its totient is φ = 11310141072.

The previous prime is 11311212097. The next prime is 11311212139. The reversal of 11311212131 is 13121211311.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11311212131 is a prime.

It is a super-2 number, since 2×11311212131² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11311212139) 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, 519530 + ... + 540863.

It is an arithmetic number, because the mean of its divisors is an integer number (2828070798).

Almost surely, 2^11311212131 is an apocalyptic number.

11311212131 is a deficient number, since it is larger than the sum of its proper divisors (1071061).

11311212131 is a wasteful number, since it uses less digits than its factorization.

11311212131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1071060.

The product of its digits is 36, while the sum is 17.

Adding to 11311212131 its reverse (13121211311), we get a palindrome (24432423442).

The spelling of 11311212131 in words is "eleven billion, three hundred eleven million, two hundred twelve thousand, one hundred thirty-one".