91646391 has 4 divisors (see below), whose sum is σ = 122195192. Its totient is φ = 61097592.

The previous prime is 91646383. The next prime is 91646393. The reversal of 91646391 is 19364619.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19364619 = 3 ⋅6454873.

It is not a de Polignac number, because 91646391 - 2³ = 91646383 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91646393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15274396 + ... + 15274401.

It is an arithmetic number, because the mean of its divisors is an integer number (30548798).

Almost surely, 2^91646391 is an apocalyptic number.

91646391 is a deficient number, since it is larger than the sum of its proper divisors (30548801).

91646391 is a wasteful number, since it uses less digits than its factorization.

91646391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30548800.

The product of its digits is 34992, while the sum is 39.

The square root of 91646391 is about 9573.2121568468. The cubic root of 91646391 is about 450.8566250742.

The spelling of 91646391 in words is "ninety-one million, six hundred forty-six thousand, three hundred ninety-one".