91161439 has 2 divisors, whose sum is σ = 91161440. Its totient is φ = 91161438.

The previous prime is 91161437. The next prime is 91161461. The reversal of 91161439 is 93416119.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 91161439 - 2¹ = 91161437 is a prime.

Together with 91161437, 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 (91161437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45580719 + 45580720.

It is an arithmetic number, because the mean of its divisors is an integer number (45580720).

Almost surely, 2^91161439 is an apocalyptic number.

91161439 is a deficient number, since it is larger than the sum of its proper divisors (1).

91161439 is an equidigital number, since it uses as much as digits as its factorization.

91161439 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5832, while the sum is 34.

The square root of 91161439 is about 9547.8499674010. The cubic root of 91161439 is about 450.0599738996.

The spelling of 91161439 in words is "ninety-one million, one hundred sixty-one thousand, four hundred thirty-nine".