131220915989 has 2 divisors, whose sum is σ = 131220915990. Its totient is φ = 131220915988.

The previous prime is 131220915983. The next prime is 131220916031. The reversal of 131220915989 is 989519022131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 104338690225 + 26882225764 = 323015^2 + 163958^2 .

It is an emirp because it is prime and its reverse (989519022131) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 131220915989 - 2³² = 126925948693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (131220915983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65610457994 + 65610457995.

It is an arithmetic number, because the mean of its divisors is an integer number (65610457995).

Almost surely, 2^131220915989 is an apocalyptic number.

It is an amenable number.

131220915989 is a deficient number, since it is larger than the sum of its proper divisors (1).

131220915989 is an equidigital number, since it uses as much as digits as its factorization.

131220915989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 349920, while the sum is 50.

The spelling of 131220915989 in words is "one hundred thirty-one billion, two hundred twenty million, nine hundred fifteen thousand, nine hundred eighty-nine".