91551191 has 4 divisors (see below), whose sum is σ = 91891800. Its totient is φ = 91210584.

The previous prime is 91551169. The next prime is 91551197. The reversal of 91551191 is 19115519.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 91551191 - 2⁶ = 91551127 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 (91551197) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 169901 + ... + 170438.

It is an arithmetic number, because the mean of its divisors is an integer number (22972950).

Almost surely, 2^91551191 is an apocalyptic number.

91551191 is a deficient number, since it is larger than the sum of its proper divisors (340609).

91551191 is a wasteful number, since it uses less digits than its factorization.

91551191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340608.

The product of its digits is 2025, while the sum is 32.

The square root of 91551191 is about 9568.2386571406. The cubic root of 91551191 is about 450.7004580909.

The spelling of 91551191 in words is "ninety-one million, five hundred fifty-one thousand, one hundred ninety-one".