1987986656 has 24 divisors (see below), whose sum is σ = 4048810920. Its totient is φ = 959717248.

The previous prime is 1987986629. The next prime is 1987986661. The reversal of 1987986656 is 6566897891.

It is a junction number, because it is equal to n+sod(n) for n = 1987986592 and 1987986601.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1070186 + ... + 1072041.

It is an arithmetic number, because the mean of its divisors is an integer number (168700455).

Almost surely, 2^1987986656 is an apocalyptic number.

1987986656 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1987986656 is an abundant number, since it is smaller than the sum of its proper divisors (2060824264).

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

1987986656 is a wasteful number, since it uses less digits than its factorization.

1987986656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2142266 (or 2142258 counting only the distinct ones).

The product of its digits is 39191040, while the sum is 65.

The square root of 1987986656 is about 44586.8439789138. The cubic root of 1987986656 is about 1257.3933379091.

The spelling of 1987986656 in words is "one billion, nine hundred eighty-seven million, nine hundred eighty-six thousand, six hundred fifty-six".