91453721 has 2 divisors, whose sum is σ = 91453722. Its totient is φ = 91453720.

The previous prime is 91453711. The next prime is 91453723. The reversal of 91453721 is 12735419.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 83814025 + 7639696 = 9155^2 + 2764^2 .

It is an emirp because it is prime and its reverse (12735419) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91453721 is a prime.

Together with 91453723, 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 (91453723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45726860 + 45726861.

It is an arithmetic number, because the mean of its divisors is an integer number (45726861).

Almost surely, 2^91453721 is an apocalyptic number.

It is an amenable number.

91453721 is a deficient number, since it is larger than the sum of its proper divisors (1).

91453721 is an equidigital number, since it uses as much as digits as its factorization.

91453721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7560, while the sum is 32.

The square root of 91453721 is about 9563.1438868188. The cubic root of 91453721 is about 450.5404551740.

The spelling of 91453721 in words is "ninety-one million, four hundred fifty-three thousand, seven hundred twenty-one".