131543999 has 4 divisors (see below), whose sum is σ = 133700520. Its totient is φ = 129387480.

The previous prime is 131543989. The next prime is 131544001. The reversal of 131543999 is 999345131.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 131543999 - 2¹⁶ = 131478463 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131543989) 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, 1078169 + ... + 1078290.

It is an arithmetic number, because the mean of its divisors is an integer number (33425130).

Almost surely, 2^131543999 is an apocalyptic number.

131543999 is a deficient number, since it is larger than the sum of its proper divisors (2156521).

131543999 is an equidigital number, since it uses as much as digits as its factorization.

131543999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2156520.

The product of its digits is 131220, while the sum is 44.

The square root of 131543999 is about 11469.2632282985. The cubic root of 131543999 is about 508.5773487845.

The spelling of 131543999 in words is "one hundred thirty-one million, five hundred forty-three thousand, nine hundred ninety-nine".