91509851 has 2 divisors, whose sum is σ = 91509852. Its totient is φ = 91509850.

The previous prime is 91509811. The next prime is 91509857. The reversal of 91509851 is 15890519.

It is a strong prime.

It is an emirp because it is prime and its reverse (15890519) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91509851 - 2¹⁸ = 91247707 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (91509857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45754925 + 45754926.

It is an arithmetic number, because the mean of its divisors is an integer number (45754926).

Almost surely, 2^91509851 is an apocalyptic number.

91509851 is a deficient number, since it is larger than the sum of its proper divisors (1).

91509851 is an equidigital number, since it uses as much as digits as its factorization.

91509851 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16200, while the sum is 38.

The square root of 91509851 is about 9566.0781410147. The cubic root of 91509851 is about 450.6326098490.

The spelling of 91509851 in words is "ninety-one million, five hundred nine thousand, eight hundred fifty-one".