20387878686 has 160 divisors (see below), whose sum is σ = 54048411648. Its totient is φ = 5621114880.

The previous prime is 20387878681. The next prime is 20387878723. The reversal of 20387878686 is 68687878302.

20387878686 is a `hidden beast` number, since 20 + 387 + 87 + 86 + 86 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20387878681) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 17681886 + ... + 17683038.

Almost surely, 2^20387878686 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20387878686, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27024205824).

20387878686 is an abundant number, since it is smaller than the sum of its proper divisors (33660532962).

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

20387878686 is a wasteful number, since it uses less digits than its factorization.

20387878686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1708 (or 1699 counting only the distinct ones).

The product of its (nonzero) digits is 43352064, while the sum is 63.

The spelling of 20387878686 in words is "twenty billion, three hundred eighty-seven million, eight hundred seventy-eight thousand, six hundred eighty-six".