91816533 has 6 divisors (see below), whose sum is σ = 132623894. Its totient is φ = 61211016.

The previous prime is 91816519. The next prime is 91816537. The reversal of 91816533 is 33561819.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 63011844 + 28804689 = 7938^2 + 5367^2 .

It is not a de Polignac number, because 91816533 - 2¹⁰ = 91815509 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 (91816537) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5100910 + ... + 5100927.

Almost surely, 2^91816533 is an apocalyptic number.

It is an amenable number.

91816533 is a deficient number, since it is larger than the sum of its proper divisors (40807361).

91816533 is a wasteful number, since it uses less digits than its factorization.

91816533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10201843 (or 10201840 counting only the distinct ones).

The product of its digits is 19440, while the sum is 36.

The square root of 91816533 is about 9582.0943952771. The cubic root of 91816533 is about 451.1354584807.

The spelling of 91816533 in words is "ninety-one million, eight hundred sixteen thousand, five hundred thirty-three".