131215009 has 2 divisors, whose sum is σ = 131215010. Its totient is φ = 131215008.

The previous prime is 131214991. The next prime is 131215013. The reversal of 131215009 is 900512131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 125104225 + 6110784 = 11185^2 + 2472^2 .

It is an emirp because it is prime and its reverse (900512131) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-131215009 is a prime.

It is not a weakly prime, because it can be changed into another prime (131215079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65607504 + 65607505.

It is an arithmetic number, because the mean of its divisors is an integer number (65607505).

Almost surely, 2^131215009 is an apocalyptic number.

It is an amenable number.

131215009 is a deficient number, since it is larger than the sum of its proper divisors (1).

131215009 is an equidigital number, since it uses as much as digits as its factorization.

131215009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 270, while the sum is 22.

The square root of 131215009 is about 11454.9120031539. The cubic root of 131215009 is about 508.1530128380.

The spelling of 131215009 in words is "one hundred thirty-one million, two hundred fifteen thousand, nine".