11911831 has 4 divisors (see below), whose sum is σ = 11955112. Its totient is φ = 11868552.

The previous prime is 11911829. The next prime is 11911859. The reversal of 11911831 is 13811911.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13811911 = 457 ⋅30223.

It is a cyclic number.

It is not a de Polignac number, because 11911831 - 2¹ = 11911829 is a prime.

It is a super-2 number, since 2×11911831² = 283783435545122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11911796 and 11911805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11911811) 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, 21225 + ... + 21778.

It is an arithmetic number, because the mean of its divisors is an integer number (2988778).

Almost surely, 2^11911831 is an apocalyptic number.

11911831 is a deficient number, since it is larger than the sum of its proper divisors (43281).

11911831 is an equidigital number, since it uses as much as digits as its factorization.

11911831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43280.

The product of its digits is 216, while the sum is 25.

The square root of 11911831 is about 3451.3520539058. The cubic root of 11911831 is about 228.3807567803.

The spelling of 11911831 in words is "eleven million, nine hundred eleven thousand, eight hundred thirty-one".