131666431 has 4 divisors (see below), whose sum is σ = 141794632. Its totient is φ = 121538232.

The previous prime is 131666429. The next prime is 131666443. The reversal of 131666431 is 134666131.

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 131666431 - 2¹ = 131666429 is a prime.

It is a super-2 number, since 2×131666431² = 34672098104555522, 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 = 131666393 and 131666402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131666401) 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, 5064081 + ... + 5064106.

It is an arithmetic number, because the mean of its divisors is an integer number (35448658).

Almost surely, 2^131666431 is an apocalyptic number.

131666431 is a deficient number, since it is larger than the sum of its proper divisors (10128201).

131666431 is a wasteful number, since it uses less digits than its factorization.

131666431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10128200.

The product of its digits is 7776, while the sum is 31.

The square root of 131666431 is about 11474.5993829850. The cubic root of 131666431 is about 508.7350826600.

The spelling of 131666431 in words is "one hundred thirty-one million, six hundred sixty-six thousand, four hundred thirty-one".