13871561 has 6 divisors (see below), whose sum is σ = 15247386. Its totient is φ = 12610400.

The previous prime is 13871551. The next prime is 13871573. The reversal of 13871561 is 16517831.

It can be written as a sum of positive squares in only one way, i.e., 13097161 + 774400 = 3619^2 + 880^2 .

It is not a de Polignac number, because 13871561 - 2¹⁰ = 13870537 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13871551) 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 5 ways as a sum of consecutive naturals, for example, 57200 + ... + 57441.

It is an arithmetic number, because the mean of its divisors is an integer number (2541231).

Almost surely, 2^13871561 is an apocalyptic number.

13871561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

13871561 is a deficient number, since it is larger than the sum of its proper divisors (1375825).

13871561 is a wasteful number, since it uses less digits than its factorization.

13871561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114663 (or 114652 counting only the distinct ones).

The product of its digits is 5040, while the sum is 32.

The square root of 13871561 is about 3724.4544566956. The cubic root of 13871561 is about 240.2749222223.

The spelling of 13871561 in words is "thirteen million, eight hundred seventy-one thousand, five hundred sixty-one".