99686815 has 4 divisors (see below), whose sum is σ = 119624184. Its totient is φ = 79749448.

The previous prime is 99686801. The next prime is 99686819. The reversal of 99686815 is 51868699.

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 99686815 - 2¹⁵ = 99654047 is a prime.

It is a super-2 number, since 2×99686815² = 19874922169688450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99686819) 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, 9968677 + ... + 9968686.

It is an arithmetic number, because the mean of its divisors is an integer number (29906046).

Almost surely, 2^99686815 is an apocalyptic number.

99686815 is a deficient number, since it is larger than the sum of its proper divisors (19937369).

99686815 is a wasteful number, since it uses less digits than its factorization.

99686815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19937368.

The product of its digits is 933120, while the sum is 52.

The square root of 99686815 is about 9984.3284701576. The cubic root of 99686815 is about 463.6738179580.

The spelling of 99686815 in words is "ninety-nine million, six hundred eighty-six thousand, eight hundred fifteen".