387878904021 has 16 divisors (see below), whose sum is σ = 622161651200. Its totient is φ = 209979556848.

The previous prime is 387878904019. The next prime is 387878904043. The reversal of 387878904021 is 120409878783.

It is not a de Polignac number, because 387878904021 - 2¹ = 387878904019 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (387878900021) 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 15 ways as a sum of consecutive naturals, for example, 486063391 + ... + 486064188.

It is an arithmetic number, because the mean of its divisors is an integer number (38885103200).

Almost surely, 2^387878904021 is an apocalyptic number.

It is an amenable number.

387878904021 is a deficient number, since it is larger than the sum of its proper divisors (234282747179).

387878904021 is a wasteful number, since it uses less digits than its factorization.

387878904021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 972127608.

The product of its (nonzero) digits is 5419008, while the sum is 57.

The spelling of 387878904021 in words is "three hundred eighty-seven billion, eight hundred seventy-eight million, nine hundred four thousand, twenty-one".