91294781 has 2 divisors, whose sum is σ = 91294782. Its totient is φ = 91294780.

The previous prime is 91294747. The next prime is 91294787. The reversal of 91294781 is 18749219.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77352025 + 13942756 = 8795^2 + 3734^2 .

It is a cyclic number.

It is not a de Polignac number, because 91294781 - 2⁶ = 91294717 is a prime.

It is a super-2 number, since 2×91294781² = 16669474075675922, which contains 22 as substring.

It is equal to p_5287829 and since 91294781 and 5287829 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91294787) 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, 45647390 + 45647391.

It is an arithmetic number, because the mean of its divisors is an integer number (45647391).

Almost surely, 2^91294781 is an apocalyptic number.

It is an amenable number.

91294781 is a deficient number, since it is larger than the sum of its proper divisors (1).

91294781 is an equidigital number, since it uses as much as digits as its factorization.

91294781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36288, while the sum is 41.

The square root of 91294781 is about 9554.8302444366. The cubic root of 91294781 is about 450.2793015072.

The spelling of 91294781 in words is "ninety-one million, two hundred ninety-four thousand, seven hundred eighty-one".