13861531 has 4 divisors (see below), whose sum is σ = 13869000. Its totient is φ = 13854064.

The previous prime is 13861513. The next prime is 13861553. The reversal of 13861531 is 13516831.

13861531 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 13516831 = 137 ⋅98663.

It is a cyclic number.

It is not a de Polignac number, because 13861531 - 2⁵ = 13861499 is a prime.

It is a super-2 number, since 2×13861531² = 384284083327922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 13861531.

It is not an unprimeable number, because it can be changed into a prime (13864531) 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, 1440 + ... + 5458.

It is an arithmetic number, because the mean of its divisors is an integer number (3467250).

Almost surely, 2^13861531 is an apocalyptic number.

13861531 is a deficient number, since it is larger than the sum of its proper divisors (7469).

13861531 is an equidigital number, since it uses as much as digits as its factorization.

13861531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7468.

The product of its digits is 2160, while the sum is 28.

The square root of 13861531 is about 3723.1077072790. The cubic root of 13861531 is about 240.2169970291.

The spelling of 13861531 in words is "thirteen million, eight hundred sixty-one thousand, five hundred thirty-one".