91909901 has 2 divisors, whose sum is σ = 91909902. Its totient is φ = 91909900.

The previous prime is 91909891. The next prime is 91909907. The reversal of 91909901 is 10990919.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 79477225 + 12432676 = 8915^2 + 3526^2 .

It is a cyclic number.

It is not a de Polignac number, because 91909901 - 2¹⁸ = 91647757 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91909907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45954950 + 45954951.

It is an arithmetic number, because the mean of its divisors is an integer number (45954951).

Almost surely, 2^91909901 is an apocalyptic number.

It is an amenable number.

91909901 is a deficient number, since it is larger than the sum of its proper divisors (1).

91909901 is an equidigital number, since it uses as much as digits as its factorization.

91909901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6561, while the sum is 38.

The square root of 91909901 is about 9586.9651610924. The cubic root of 91909901 is about 451.2883261774.

It can be divided in two parts, 9190 and 9901, that added together give a palindrome (19091).

The spelling of 91909901 in words is "ninety-one million, nine hundred nine thousand, nine hundred one".