91156393 has 2 divisors, whose sum is σ = 91156394. Its totient is φ = 91156392.

The previous prime is 91156391. The next prime is 91156463. The reversal of 91156393 is 39365119.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67371264 + 23785129 = 8208^2 + 4877^2 .

It is a cyclic number.

It is not a de Polignac number, because 91156393 - 2¹ = 91156391 is a prime.

Together with 91156391, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (91156391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45578196 + 45578197.

It is an arithmetic number, because the mean of its divisors is an integer number (45578197).

Almost surely, 2^91156393 is an apocalyptic number.

It is an amenable number.

91156393 is a deficient number, since it is larger than the sum of its proper divisors (1).

91156393 is an equidigital number, since it uses as much as digits as its factorization.

91156393 is an evil number, because the sum of its binary digits is even.

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

The square root of 91156393 is about 9547.5857157713. The cubic root of 91156393 is about 450.0516697871.

The spelling of 91156393 in words is "ninety-one million, one hundred fifty-six thousand, three hundred ninety-three".