91989851 has 2 divisors, whose sum is σ = 91989852. Its totient is φ = 91989850.

The previous prime is 91989841. The next prime is 91989869. The reversal of 91989851 is 15898919.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91989851 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 91989851.

It is not a weakly prime, because it can be changed into another prime (91989841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45994925 + 45994926.

It is an arithmetic number, because the mean of its divisors is an integer number (45994926).

Almost surely, 2^91989851 is an apocalyptic number.

91989851 is a deficient number, since it is larger than the sum of its proper divisors (1).

91989851 is an equidigital number, since it uses as much as digits as its factorization.

91989851 is an evil number, because the sum of its binary digits is even.

The product of its digits is 233280, while the sum is 50.

The square root of 91989851 is about 9591.1339788369. The cubic root of 91989851 is about 451.4191428596.

The spelling of 91989851 in words is "ninety-one million, nine hundred eighty-nine thousand, eight hundred fifty-one".