388959991 has 24 divisors (see below), whose sum is σ = 462003696. Its totient is φ = 326430720.

The previous prime is 388959959. The next prime is 388959997. The reversal of 388959991 is 199959883.

It is a happy number.

It is not a de Polignac number, because 388959991 - 2⁵ = 388959959 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (388959997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 843501 + ... + 843961.

It is an arithmetic number, because the mean of its divisors is an integer number (19250154).

Almost surely, 2^388959991 is an apocalyptic number.

388959991 is a deficient number, since it is larger than the sum of its proper divisors (73043705).

388959991 is a wasteful number, since it uses less digits than its factorization.

388959991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 799 (or 792 counting only the distinct ones).

The product of its digits is 6298560, while the sum is 61.

The square root of 388959991 is about 19722.0686288229. The cubic root of 388959991 is about 729.9643386595.

The spelling of 388959991 in words is "three hundred eighty-eight million, nine hundred fifty-nine thousand, nine hundred ninety-one".