131681905 has 4 divisors (see below), whose sum is σ = 158018292. Its totient is φ = 105345520.

The previous prime is 131681903. The next prime is 131681929. The reversal of 131681905 is 509186131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 509186131 = 67 ⋅7599793.

It can be written as a sum of positive squares in 2 ways, for example, as 99680256 + 32001649 = 9984^2 + 5657^2 .

It is not a de Polignac number, because 131681905 - 2¹ = 131681903 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131681903) 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, 13168186 + ... + 13168195.

It is an arithmetic number, because the mean of its divisors is an integer number (39504573).

Almost surely, 2^131681905 is an apocalyptic number.

It is an amenable number.

131681905 is a deficient number, since it is larger than the sum of its proper divisors (26336387).

131681905 is an equidigital number, since it uses as much as digits as its factorization.

131681905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26336386.

The product of its (nonzero) digits is 6480, while the sum is 34.

The square root of 131681905 is about 11475.2736350816. The cubic root of 131681905 is about 508.7550114509.

The spelling of 131681905 in words is "one hundred thirty-one million, six hundred eighty-one thousand, nine hundred five".