91726421 has 2 divisors, whose sum is σ = 91726422. Its totient is φ = 91726420.

The previous prime is 91726409. The next prime is 91726501. The reversal of 91726421 is 12462719.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 91680625 + 45796 = 9575^2 + 214^2 .

It is an emirp because it is prime and its reverse (12462719) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91726421 - 2¹⁴ = 91710037 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91726121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45863210 + 45863211.

It is an arithmetic number, because the mean of its divisors is an integer number (45863211).

Almost surely, 2^91726421 is an apocalyptic number.

It is an amenable number.

91726421 is a deficient number, since it is larger than the sum of its proper divisors (1).

91726421 is an equidigital number, since it uses as much as digits as its factorization.

91726421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6048, while the sum is 32.

The square root of 91726421 is about 9577.3911374654. The cubic root of 91726421 is about 450.9878233955.

The spelling of 91726421 in words is "ninety-one million, seven hundred twenty-six thousand, four hundred twenty-one".