91648421 has 2 divisors, whose sum is σ = 91648422. Its totient is φ = 91648420.

The previous prime is 91648409. The next prime is 91648423. The reversal of 91648421 is 12484619.

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., 72165025 + 19483396 = 8495^2 + 4414^2 .

It is a cyclic number.

It is not a de Polignac number, because 91648421 - 2⁶ = 91648357 is a prime.

Together with 91648423, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91648423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45824210 + 45824211.

It is an arithmetic number, because the mean of its divisors is an integer number (45824211).

Almost surely, 2^91648421 is an apocalyptic number.

It is an amenable number.

91648421 is a deficient number, since it is larger than the sum of its proper divisors (1).

91648421 is an equidigital number, since it uses as much as digits as its factorization.

91648421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13824, while the sum is 35.

The square root of 91648421 is about 9573.3181812786. The cubic root of 91648421 is about 450.8599539276.

The spelling of 91648421 in words is "ninety-one million, six hundred forty-eight thousand, four hundred twenty-one".