131191421 has 2 divisors, whose sum is σ = 131191422. Its totient is φ = 131191420.

The previous prime is 131191387. The next prime is 131191441. The reversal of 131191421 is 124191131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 130279396 + 912025 = 11414^2 + 955^2 .

It is an emirp because it is prime and its reverse (124191131) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-131191421 is a prime.

It is a super-2 number, since 2×131191421² = 34422377887998482, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (131191441) 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, 65595710 + 65595711.

It is an arithmetic number, because the mean of its divisors is an integer number (65595711).

Almost surely, 2^131191421 is an apocalyptic number.

It is an amenable number.

131191421 is a deficient number, since it is larger than the sum of its proper divisors (1).

131191421 is an equidigital number, since it uses as much as digits as its factorization.

131191421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 216, while the sum is 23.

The square root of 131191421 is about 11453.8823549048. The cubic root of 131191421 is about 508.1225614650.

The spelling of 131191421 in words is "one hundred thirty-one million, one hundred ninety-one thousand, four hundred twenty-one".