99840425 has 6 divisors (see below), whose sum is σ = 123802158. Its totient is φ = 79872320.

The previous prime is 99840409. The next prime is 99840443. The reversal of 99840425 is 52404899.

It can be written as a sum of positive squares in 3 ways, for example, as 361 + 99840064 = 19^2 + 9992^2 .

It is not a de Polignac number, because 99840425 - 2⁴ = 99840409 is a prime.

It is a super-2 number, since 2×99840425² = 19936220928361250, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1996784 + ... + 1996833.

It is an arithmetic number, because the mean of its divisors is an integer number (20633693).

Almost surely, 2^99840425 is an apocalyptic number.

It is an amenable number.

99840425 is a deficient number, since it is larger than the sum of its proper divisors (23961733).

99840425 is a wasteful number, since it uses less digits than its factorization.

99840425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3993627 (or 3993622 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 41.

The square root of 99840425 is about 9992.0180644352. The cubic root of 99840425 is about 463.9118580717.

The spelling of 99840425 in words is "ninety-nine million, eight hundred forty thousand, four hundred twenty-five".