15643993938 has 32 divisors (see below), whose sum is σ = 32941218240. Its totient is φ = 4939234560.

The previous prime is 15643993933. The next prime is 15643993993. The reversal of 15643993938 is 83939934651.

15643993938 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (15643993933) 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 in 15 ways as a sum of consecutive naturals, for example, 760606 + ... + 780902.

It is an arithmetic number, because the mean of its divisors is an integer number (1029413070).

Almost surely, 2^15643993938 is an apocalyptic number.

15643993938 is an abundant number, since it is smaller than the sum of its proper divisors (17297224302).

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

15643993938 is a wasteful number, since it uses less digits than its factorization.

15643993938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27082.

The product of its digits is 18895680, while the sum is 60.

The spelling of 15643993938 in words is "fifteen billion, six hundred forty-three million, nine hundred ninety-three thousand, nine hundred thirty-eight".