13218831 has 6 divisors (see below), whose sum is σ = 19093880. Its totient is φ = 8812548.

The previous prime is 13218827. The next prime is 13218839. The reversal of 13218831 is 13881231.

13218831 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 13218831 - 2² = 13218827 is a prime.

It is a super-2 number, since 2×13218831² = 349474986013122, 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 = 13218795 and 13218804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13218839) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 734371 + ... + 734388.

Almost surely, 2^13218831 is an apocalyptic number.

13218831 is a deficient number, since it is larger than the sum of its proper divisors (5875049).

13218831 is a wasteful number, since it uses less digits than its factorization.

13218831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1468765 (or 1468762 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 13218831 is about 3635.7710323946. The cubic root of 13218831 is about 236.4454802685.

The spelling of 13218831 in words is "thirteen million, two hundred eighteen thousand, eight hundred thirty-one".