9905868787 has 4 divisors (see below), whose sum is σ = 9908382456. Its totient is φ = 9903355120.

The previous prime is 9905868767. The next prime is 9905868799. The reversal of 9905868787 is 7878685099.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7878685099 = 3701 ⋅2128799.

It is a cyclic number.

It is not a de Polignac number, because 9905868787 - 2¹⁵ = 9905836019 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9905868757) 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, 1250914 + ... + 1258807.

It is an arithmetic number, because the mean of its divisors is an integer number (2477095614).

Almost surely, 2^9905868787 is an apocalyptic number.

9905868787 is a deficient number, since it is larger than the sum of its proper divisors (2513669).

9905868787 is a wasteful number, since it uses less digits than its factorization.

9905868787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2513668.

The product of its (nonzero) digits is 60963840, while the sum is 67.

The square root of 9905868787 is about 99528.2311055512. The cubic root of 9905868787 is about 2147.6533825321.

The spelling of 9905868787 in words is "nine billion, nine hundred five million, eight hundred sixty-eight thousand, seven hundred eighty-seven".