131219989 has 2 divisors, whose sum is σ = 131219990. Its totient is φ = 131219988.

The previous prime is 131219987. The next prime is 131220017. The reversal of 131219989 is 989912131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 130302225 + 917764 = 11415^2 + 958^2 .

It is a cyclic number.

It is not a de Polignac number, because 131219989 - 2¹ = 131219987 is a prime.

Together with 131219987, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (131219987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65609994 + 65609995.

It is an arithmetic number, because the mean of its divisors is an integer number (65609995).

Almost surely, 2^131219989 is an apocalyptic number.

It is an amenable number.

131219989 is a deficient number, since it is larger than the sum of its proper divisors (1).

131219989 is an equidigital number, since it uses as much as digits as its factorization.

131219989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34992, while the sum is 43.

The square root of 131219989 is about 11455.1293750878. The cubic root of 131219989 is about 508.1594413963.

The spelling of 131219989 in words is "one hundred thirty-one million, two hundred nineteen thousand, nine hundred eighty-nine".