91381673 has 2 divisors, whose sum is σ = 91381674. Its totient is φ = 91381672.

The previous prime is 91381637. The next prime is 91381679. The reversal of 91381673 is 37618319.

Together with previous prime (91381637) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48832144 + 42549529 = 6988^2 + 6523^2 .

It is a cyclic number.

It is not a de Polignac number, because 91381673 - 2¹⁰ = 91380649 is a prime.

It is a super-2 number, since 2×91381673² = 16701220320557858, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (91381679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45690836 + 45690837.

It is an arithmetic number, because the mean of its divisors is an integer number (45690837).

Almost surely, 2^91381673 is an apocalyptic number.

It is an amenable number.

91381673 is a deficient number, since it is larger than the sum of its proper divisors (1).

91381673 is an equidigital number, since it uses as much as digits as its factorization.

91381673 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27216, while the sum is 38.

The square root of 91381673 is about 9559.3761825759. The cubic root of 91381673 is about 450.4221109218.

The spelling of 91381673 in words is "ninety-one million, three hundred eighty-one thousand, six hundred seventy-three".