9991438102 has 4 divisors (see below), whose sum is σ = 14987157156. Its totient is φ = 4995719050.

The previous prime is 9991438031. The next prime is 9991438103. The reversal of 9991438102 is 2018341999.

It is a happy number.

9991438102 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9991438103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2497859524 + ... + 2497859527.

It is an arithmetic number, because the mean of its divisors is an integer number (3746789289).

Almost surely, 2^9991438102 is an apocalyptic number.

9991438102 is a deficient number, since it is larger than the sum of its proper divisors (4995719054).

9991438102 is a wasteful number, since it uses less digits than its factorization.

9991438102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4995719053.

The product of its (nonzero) digits is 139968, while the sum is 46.

The square root of 9991438102 is about 99957.1813428130. The cubic root of 9991438102 is about 2153.8196461316.

The spelling of 9991438102 in words is "nine billion, nine hundred ninety-one million, four hundred thirty-eight thousand, one hundred two".