91821701 has 2 divisors, whose sum is σ = 91821702. Its totient is φ = 91821700.

The previous prime is 91821683. The next prime is 91821703. The reversal of 91821701 is 10712819.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77457601 + 14364100 = 8801^2 + 3790^2 .

It is a cyclic number.

It is not a de Polignac number, because 91821701 - 2⁶ = 91821637 is a prime.

It is a Sophie Germain prime.

Together with 91821703, it forms a pair of twin primes.

It is a Chen 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 (91821703) 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, 45910850 + 45910851.

It is an arithmetic number, because the mean of its divisors is an integer number (45910851).

Almost surely, 2^91821701 is an apocalyptic number.

It is an amenable number.

91821701 is a deficient number, since it is larger than the sum of its proper divisors (1).

91821701 is an equidigital number, since it uses as much as digits as its factorization.

91821701 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 29.

The square root of 91821701 is about 9582.3640611281. The cubic root of 91821701 is about 451.1439225494.

The spelling of 91821701 in words is "ninety-one million, eight hundred twenty-one thousand, seven hundred one".