91391633 has 2 divisors, whose sum is σ = 91391634. Its totient is φ = 91391632.

The previous prime is 91391623. The next prime is 91391639. The reversal of 91391633 is 33619319.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 76860289 + 14531344 = 8767^2 + 3812^2 .

It is a cyclic number.

It is not a de Polignac number, because 91391633 - 2⁴ = 91391617 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 91391593 and 91391602.

It is not a weakly prime, because it can be changed into another prime (91391639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45695816 + 45695817.

It is an arithmetic number, because the mean of its divisors is an integer number (45695817).

Almost surely, 2^91391633 is an apocalyptic number.

It is an amenable number.

91391633 is a deficient number, since it is larger than the sum of its proper divisors (1).

91391633 is an equidigital number, since it uses as much as digits as its factorization.

91391633 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13122, while the sum is 35.

The square root of 91391633 is about 9559.8971228774. The cubic root of 91391633 is about 450.4384746743.

The spelling of 91391633 in words is "ninety-one million, three hundred ninety-one thousand, six hundred thirty-three".