20386587816 has 128 divisors (see below), whose sum is σ = 68526432000. Its totient is φ = 5482100736.

The previous prime is 20386587797. The next prime is 20386587817. The reversal of 20386587816 is 61878568302.

20386587816 is a `hidden beast` number, since 20 + 38 + 6 + 587 + 8 + 1 + 6 = 666.

It is a super-2 number, since 2×20386587816² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (20386587817) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 370861 + ... + 422268.

It is an arithmetic number, because the mean of its divisors is an integer number (535362750).

Almost surely, 2^20386587816 is an apocalyptic number.

It is an amenable number.

20386587816 is an abundant number, since it is smaller than the sum of its proper divisors (48139844184).

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

20386587816 is a wasteful number, since it uses less digits than its factorization.

20386587816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 793168 (or 793158 counting only the distinct ones).

The product of its (nonzero) digits is 3870720, while the sum is 54.

The spelling of 20386587816 in words is "twenty billion, three hundred eighty-six million, five hundred eighty-seven thousand, eight hundred sixteen".