91278233 has 2 divisors, whose sum is σ = 91278234. Its totient is φ = 91278232.

The previous prime is 91278227. The next prime is 91278247. The reversal of 91278233 is 33287219.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 80335369 + 10942864 = 8963^2 + 3308^2 .

It is a cyclic number.

It is not a de Polignac number, because 91278233 - 2⁴ = 91278217 is a prime.

It is a super-4 number, since 4×91278233⁴ (a number of 33 digits) contains 4444 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 91278193 and 91278202.

It is not a weakly prime, because it can be changed into another prime (91278203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45639116 + 45639117.

It is an arithmetic number, because the mean of its divisors is an integer number (45639117).

Almost surely, 2^91278233 is an apocalyptic number.

It is an amenable number.

91278233 is a deficient number, since it is larger than the sum of its proper divisors (1).

91278233 is an equidigital number, since it uses as much as digits as its factorization.

91278233 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18144, while the sum is 35.

The square root of 91278233 is about 9553.9642557422. The cubic root of 91278233 is about 450.2520941391.

The spelling of 91278233 in words is "ninety-one million, two hundred seventy-eight thousand, two hundred thirty-three".