387878919021 has 72 divisors (see below), whose sum is σ = 644891327808. Its totient is φ = 224058700800.

The previous prime is 387878919007. The next prime is 387878919041. The reversal of 387878919021 is 120919878783.

387878919021 is a `hidden beast` number, since 387 + 87 + 8 + 91 + 90 + 2 + 1 = 666.

It is not a de Polignac number, because 387878919021 - 2¹¹ = 387878916973 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 387878919021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (387878919041) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 7060941 + ... + 7115661.

Almost surely, 2^387878919021 is an apocalyptic number.

It is an amenable number.

387878919021 is a deficient number, since it is larger than the sum of its proper divisors (257012408787).

387878919021 is a wasteful number, since it uses less digits than its factorization.

387878919021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55055 (or 55041 counting only the distinct ones).

The product of its (nonzero) digits is 12192768, while the sum is 63.

The spelling of 387878919021 in words is "three hundred eighty-seven billion, eight hundred seventy-eight million, nine hundred nineteen thousand, twenty-one".