91855397 has 2 divisors, whose sum is σ = 91855398. Its totient is φ = 91855396.

The previous prime is 91855391. The next prime is 91855453. The reversal of 91855397 is 79355819.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 63457156 + 28398241 = 7966^2 + 5329^2 .

It is a cyclic number.

It is not a de Polignac number, because 91855397 - 2⁶ = 91855333 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 (91855391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45927698 + 45927699.

It is an arithmetic number, because the mean of its divisors is an integer number (45927699).

Almost surely, 2^91855397 is an apocalyptic number.

It is an amenable number.

91855397 is a deficient number, since it is larger than the sum of its proper divisors (1).

91855397 is an equidigital number, since it uses as much as digits as its factorization.

91855397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 340200, while the sum is 47.

The square root of 91855397 is about 9584.1221298562. The cubic root of 91855397 is about 451.1991015404.

The spelling of 91855397 in words is "ninety-one million, eight hundred fifty-five thousand, three hundred ninety-seven".