99897819 has 24 divisors (see below), whose sum is σ = 156192768. Its totient is φ = 56624400.

The previous prime is 99897773. The next prime is 99897881. The reversal of 99897819 is 91879899.

It is not a de Polignac number, because 99897819 - 2⁷ = 99897691 is a prime.

It is a super-4 number, since 4×99897819⁴ (a number of 33 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is not an unprimeable number, because it can be changed into a prime (99898819) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15994 + ... + 21344.

It is an arithmetic number, because the mean of its divisors is an integer number (6508032).

Almost surely, 2^99897819 is an apocalyptic number.

99897819 is a deficient number, since it is larger than the sum of its proper divisors (56294949).

99897819 is a wasteful number, since it uses less digits than its factorization.

99897819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5495 (or 5488 counting only the distinct ones).

The product of its digits is 2939328, while the sum is 60.

The square root of 99897819 is about 9994.8896442132. The cubic root of 99897819 is about 464.0007354205. Note that the first 3 decimals are identical.

The spelling of 99897819 in words is "ninety-nine million, eight hundred ninety-seven thousand, eight hundred nineteen".