11131220031 has 4 divisors (see below), whose sum is σ = 14841626712. Its totient is φ = 7420813352.

The previous prime is 11131220027. The next prime is 11131220057. The reversal of 11131220031 is 13002213111.

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: 13002213111 = 3 ⋅4334071037.

It is a cyclic number.

It is not a de Polignac number, because 11131220031 - 2² = 11131220027 is a prime.

It is a super-2 number, since 2×11131220031² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11131224031) 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, 1855203336 + ... + 1855203341.

It is an arithmetic number, because the mean of its divisors is an integer number (3710406678).

Almost surely, 2^11131220031 is an apocalyptic number.

11131220031 is a deficient number, since it is larger than the sum of its proper divisors (3710406681).

11131220031 is an equidigital number, since it uses as much as digits as its factorization.

11131220031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3710406680.

The product of its (nonzero) digits is 36, while the sum is 15.

Adding to 11131220031 its reverse (13002213111), we get a palindrome (24133433142).

The spelling of 11131220031 in words is "eleven billion, one hundred thirty-one million, two hundred twenty thousand, thirty-one".