18871431 has 16 divisors (see below), whose sum is σ = 27164160. Its totient is φ = 11617760.

The previous prime is 18871429. The next prime is 18871451. The reversal of 18871431 is 13417881.

It is not a de Polignac number, because 18871431 - 2¹ = 18871429 is a prime.

It is a super-2 number, since 2×18871431² = 712261815975522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18871392 and 18871401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18871451) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2715 + ... + 6716.

It is an arithmetic number, because the mean of its divisors is an integer number (1697760).

Almost surely, 2^18871431 is an apocalyptic number.

18871431 is a deficient number, since it is larger than the sum of its proper divisors (8292729).

18871431 is a wasteful number, since it uses less digits than its factorization.

18871431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9486.

The product of its digits is 5376, while the sum is 33.

The square root of 18871431 is about 4344.1260340833. The cubic root of 18871431 is about 266.2369183989.

The spelling of 18871431 in words is "eighteen million, eight hundred seventy-one thousand, four hundred thirty-one".