91275551 has 4 divisors (see below), whose sum is σ = 93217632. Its totient is φ = 89333472.

The previous prime is 91275539. The next prime is 91275571. The reversal of 91275551 is 15557219.

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 91275551 - 2¹⁰ = 91274527 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 (91275521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 970970 + ... + 971063.

It is an arithmetic number, because the mean of its divisors is an integer number (23304408).

Almost surely, 2^91275551 is an apocalyptic number.

91275551 is a deficient number, since it is larger than the sum of its proper divisors (1942081).

91275551 is a wasteful number, since it uses less digits than its factorization.

91275551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1942080.

The product of its digits is 15750, while the sum is 35.

The square root of 91275551 is about 9553.8238941274. The cubic root of 91275551 is about 450.2476842234.

The spelling of 91275551 in words is "ninety-one million, two hundred seventy-five thousand, five hundred fifty-one".