91139801 has 2 divisors, whose sum is σ = 91139802. Its totient is φ = 91139800.

The previous prime is 91139773. The next prime is 91139803. The reversal of 91139801 is 10893119.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 45914176 + 45225625 = 6776^2 + 6725^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91139801 is a prime.

Together with 91139803, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (91139803) 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, 45569900 + 45569901.

It is an arithmetic number, because the mean of its divisors is an integer number (45569901).

Almost surely, 2^91139801 is an apocalyptic number.

It is an amenable number.

91139801 is a deficient number, since it is larger than the sum of its proper divisors (1).

91139801 is an equidigital number, since it uses as much as digits as its factorization.

91139801 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1944, while the sum is 32.

The square root of 91139801 is about 9546.7167654644. The cubic root of 91139801 is about 450.0243624670.

The spelling of 91139801 in words is "ninety-one million, one hundred thirty-nine thousand, eight hundred one".