999993906 has 12 divisors (see below), whose sum is σ = 2166653502. Its totient is φ = 333331296.

The previous prime is 999993901. The next prime is 999993913. The reversal of 999993906 is 609399999.

It can be written as a sum of positive squares in only one way, i.e., 568393281 + 431600625 = 23841^2 + 20775^2 .

It is not an unprimeable number, because it can be changed into a prime (999993901) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 27777591 + ... + 27777626.

Almost surely, 2^999993906 is an apocalyptic number.

999993906 is an abundant number, since it is smaller than the sum of its proper divisors (1166659596).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

999993906 is a wasteful number, since it uses less digits than its factorization.

999993906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55555225 (or 55555222 counting only the distinct ones).

The product of its (nonzero) digits is 9565938, while the sum is 63.

The square root of 999993906 is about 31622.6802469367. The cubic root of 999993906 is about 999.9979686625.

The spelling of 999993906 in words is "nine hundred ninety-nine million, nine hundred ninety-three thousand, nine hundred six".