91771969 has 2 divisors, whose sum is σ = 91771970. Its totient is φ = 91771968.

The previous prime is 91771961. The next prime is 91771987. The reversal of 91771969 is 96917719.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 88585744 + 3186225 = 9412^2 + 1785^2 .

It is an emirp because it is prime and its reverse (96917719) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91771969 - 2³ = 91771961 is a prime.

It is a super-2 number, since 2×91771969² = 16844188588273922, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (91771961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45885984 + 45885985.

It is an arithmetic number, because the mean of its divisors is an integer number (45885985).

Almost surely, 2^91771969 is an apocalyptic number.

It is an amenable number.

91771969 is a deficient number, since it is larger than the sum of its proper divisors (1).

91771969 is an equidigital number, since it uses as much as digits as its factorization.

91771969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 214326, while the sum is 49.

The square root of 91771969 is about 9579.7687341605. The cubic root of 91771969 is about 451.0624590858.

The spelling of 91771969 in words is "ninety-one million, seven hundred seventy-one thousand, nine hundred sixty-nine".