388991845 has 16 divisors (see below), whose sum is σ = 536028480. Its totient is φ = 268012800.

The previous prime is 388991833. The next prime is 388991849. The reversal of 388991845 is 548199883.

It is a de Polignac number, because none of the positive numbers 2^k-388991845 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (55).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (388991849) 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, 185076 + ... + 187165.

It is an arithmetic number, because the mean of its divisors is an integer number (33501780).

Almost surely, 2^388991845 is an apocalyptic number.

It is an amenable number.

388991845 is a deficient number, since it is larger than the sum of its proper divisors (147036635).

388991845 is a wasteful number, since it uses less digits than its factorization.

388991845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 372276.

The product of its digits is 2488320, while the sum is 55.

The square root of 388991845 is about 19722.8761847759. The cubic root of 388991845 is about 729.9842650014.

The spelling of 388991845 in words is "three hundred eighty-eight million, nine hundred ninety-one thousand, eight hundred forty-five".