91866553 has 4 divisors (see below), whose sum is σ = 91885968. Its totient is φ = 91847140.

The previous prime is 91866499. The next prime is 91866557. The reversal of 91866553 is 35566819.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 35566819 = 863 ⋅41213.

It is a cyclic number.

It is not a de Polignac number, because 91866553 - 2⁹ = 91866041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91866557) 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, 2550 + ... + 13792.

It is an arithmetic number, because the mean of its divisors is an integer number (22971492).

Almost surely, 2^91866553 is an apocalyptic number.

It is an amenable number.

91866553 is a deficient number, since it is larger than the sum of its proper divisors (19415).

91866553 is a wasteful number, since it uses less digits than its factorization.

91866553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19414.

The product of its digits is 194400, while the sum is 43.

The square root of 91866553 is about 9584.7041164556. The cubic root of 91866553 is about 451.2173671099.

The spelling of 91866553 in words is "ninety-one million, eight hundred sixty-six thousand, five hundred fifty-three".