1987639085664 has 480 divisors, whose sum is σ = 6501089548800. Its totient is φ = 593117199360.

The previous prime is 1987639085591. The next prime is 1987639085671. The reversal of 1987639085664 is 4665809367891.

1987639085664 is a `hidden beast` number, since 1 + 98 + 76 + 390 + 85 + 6 + 6 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 1987639085592 and 1987639085601.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 67110219 + ... + 67139829.

It is an arithmetic number, because the mean of its divisors is an integer number (13543936560).

Almost surely, 2^{1987639085664} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1987639085664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3250544774400).

1987639085664 is an abundant number, since it is smaller than the sum of its proper divisors (4513450463136).

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

1987639085664 is a wasteful number, since it uses less digits than its factorization.

1987639085664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29728 (or 29711 counting only the distinct ones).

The product of its (nonzero) digits is 470292480, while the sum is 72.

The spelling of 1987639085664 in words is "one trillion, nine hundred eighty-seven billion, six hundred thirty-nine million, eighty-five thousand, six hundred sixty-four".