91413821 has 2 divisors, whose sum is σ = 91413822. Its totient is φ = 91413820.

The previous prime is 91413781. The next prime is 91413827. The reversal of 91413821 is 12831419.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 46389721 + 45024100 = 6811^2 + 6710^2 .

It is an emirp because it is prime and its reverse (12831419) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91413821 - 2⁶ = 91413757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91413827) 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, 45706910 + 45706911.

It is an arithmetic number, because the mean of its divisors is an integer number (45706911).

Almost surely, 2^91413821 is an apocalyptic number.

It is an amenable number.

91413821 is a deficient number, since it is larger than the sum of its proper divisors (1).

91413821 is an equidigital number, since it uses as much as digits as its factorization.

91413821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 29.

The square root of 91413821 is about 9561.0575251904. The cubic root of 91413821 is about 450.4749241094.

The spelling of 91413821 in words is "ninety-one million, four hundred thirteen thousand, eight hundred twenty-one".