91699789 has 2 divisors, whose sum is σ = 91699790. Its totient is φ = 91699788.

The previous prime is 91699787. The next prime is 91699807. The reversal of 91699789 is 98799619.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 74684164 + 17015625 = 8642^2 + 4125^2 .

It is an emirp because it is prime and its reverse (98799619) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91699789 - 2¹ = 91699787 is a prime.

Together with 91699787, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91699787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45849894 + 45849895.

It is an arithmetic number, because the mean of its divisors is an integer number (45849895).

Almost surely, 2^91699789 is an apocalyptic number.

It is an amenable number.

91699789 is a deficient number, since it is larger than the sum of its proper divisors (1).

91699789 is an equidigital number, since it uses as much as digits as its factorization.

91699789 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2204496, while the sum is 58.

The square root of 91699789 is about 9576.0006787803. Note that the first 3 decimals coincide. The cubic root of 91699789 is about 450.9441723217.

The spelling of 91699789 in words is "ninety-one million, six hundred ninety-nine thousand, seven hundred eighty-nine".