99819647 has 4 divisors (see below), whose sum is σ = 99889800. Its totient is φ = 99749496.

The previous prime is 99819637. The next prime is 99819661. The reversal of 99819647 is 74691899.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74691899 = 439 ⋅170141.

It is a cyclic number.

It is not a de Polignac number, because 99819647 - 2⁶ = 99819583 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 (99819637) 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, 32897 + ... + 35802.

It is an arithmetic number, because the mean of its divisors is an integer number (24972450).

Almost surely, 2^99819647 is an apocalyptic number.

99819647 is a deficient number, since it is larger than the sum of its proper divisors (70153).

99819647 is a wasteful number, since it uses less digits than its factorization.

99819647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70152.

The product of its digits is 979776, while the sum is 53.

The square root of 99819647 is about 9990.9782804288. The cubic root of 99819647 is about 463.8796739495.

The spelling of 99819647 in words is "ninety-nine million, eight hundred nineteen thousand, six hundred forty-seven".