91204013 has 2 divisors, whose sum is σ = 91204014. Its totient is φ = 91204012.

The previous prime is 91203991. The next prime is 91204021. The reversal of 91204013 is 31040219.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77757124 + 13446889 = 8818^2 + 3667^2 .

It is a cyclic number.

It is not a de Polignac number, because 91204013 - 2⁶ = 91203949 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91204063) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45602006 + 45602007.

It is an arithmetic number, because the mean of its divisors is an integer number (45602007).

Almost surely, 2^91204013 is an apocalyptic number.

It is an amenable number.

91204013 is a deficient number, since it is larger than the sum of its proper divisors (1).

91204013 is an equidigital number, since it uses as much as digits as its factorization.

91204013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 91204013 is about 9550.0792143312. The cubic root of 91204013 is about 450.1300249778.

The spelling of 91204013 in words is "ninety-one million, two hundred four thousand, thirteen".