91426640909 has 2 divisors, whose sum is σ = 91426640910. Its totient is φ = 91426640908.

The previous prime is 91426640869. The next prime is 91426640927. The reversal of 91426640909 is 90904662419.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 90402448900 + 1024192009 = 300670^2 + 32003^2 .

It is a cyclic number.

It is not a de Polignac number, because 91426640909 - 2²⁰ = 91425592333 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91426640969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45713320454 + 45713320455.

It is an arithmetic number, because the mean of its divisors is an integer number (45713320455).

Almost surely, 2^91426640909 is an apocalyptic number.

It is an amenable number.

91426640909 is a deficient number, since it is larger than the sum of its proper divisors (1).

91426640909 is an equidigital number, since it uses as much as digits as its factorization.

91426640909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 839808, while the sum is 50.

The spelling of 91426640909 in words is "ninety-one billion, four hundred twenty-six million, six hundred forty thousand, nine hundred nine".