91816651 has 4 divisors (see below), whose sum is σ = 93321904. Its totient is φ = 90311400.

The previous prime is 91816649. The next prime is 91816657. The reversal of 91816651 is 15661819.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15661819 = 71 ⋅220589.

It is a cyclic number.

It is not a de Polignac number, because 91816651 - 2¹ = 91816649 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 91816651.

It is not an unprimeable number, because it can be changed into a prime (91816657) 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, 752535 + ... + 752656.

It is an arithmetic number, because the mean of its divisors is an integer number (23330476).

Almost surely, 2^91816651 is an apocalyptic number.

91816651 is a deficient number, since it is larger than the sum of its proper divisors (1505253).

91816651 is a wasteful number, since it uses less digits than its factorization.

91816651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1505252.

The product of its digits is 12960, while the sum is 37.

The square root of 91816651 is about 9582.1005525928. The cubic root of 91816651 is about 451.1356517428.

The spelling of 91816651 in words is "ninety-one million, eight hundred sixteen thousand, six hundred fifty-one".