91373987 has 2 divisors, whose sum is σ = 91373988. Its totient is φ = 91373986.

The previous prime is 91373939. The next prime is 91374001. The reversal of 91373987 is 78937319.

It is a strong prime.

It is an emirp because it is prime and its reverse (78937319) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91373987 - 2⁸ = 91373731 is a prime.

It is not a weakly prime, because it can be changed into another prime (91373927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45686993 + 45686994.

It is an arithmetic number, because the mean of its divisors is an integer number (45686994).

Almost surely, 2^91373987 is an apocalyptic number.

91373987 is a deficient number, since it is larger than the sum of its proper divisors (1).

91373987 is an equidigital number, since it uses as much as digits as its factorization.

91373987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 285768, while the sum is 47.

The square root of 91373987 is about 9558.9741604421. The cubic root of 91373987 is about 450.4094824180.

The spelling of 91373987 in words is "ninety-one million, three hundred seventy-three thousand, nine hundred eighty-seven".