91531369 has 2 divisors, whose sum is σ = 91531370. Its totient is φ = 91531368.

The previous prime is 91531367. The next prime is 91531373. The reversal of 91531369 is 96313519.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 86713344 + 4818025 = 9312^2 + 2195^2 .

It is a cyclic number.

It is not a de Polignac number, because 91531369 - 2¹ = 91531367 is a prime.

It is a super-2 number, since 2×91531369² = 16755983022028322, which contains 22 as substring.

Together with 91531367, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (91531367) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45765684 + 45765685.

It is an arithmetic number, because the mean of its divisors is an integer number (45765685).

Almost surely, 2^91531369 is an apocalyptic number.

It is an amenable number.

91531369 is a deficient number, since it is larger than the sum of its proper divisors (1).

91531369 is an equidigital number, since it uses as much as digits as its factorization.

91531369 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21870, while the sum is 37.

The square root of 91531369 is about 9567.2027782419. The cubic root of 91531369 is about 450.6679282781.

The spelling of 91531369 in words is "ninety-one million, five hundred thirty-one thousand, three hundred sixty-nine".