3987561684544 has 63 divisors (see below), whose sum is σ = 8406230090097. Its totient is φ = 1876371815424.

The previous prime is 3987561684521. The next prime is 3987561684569. The reversal of 3987561684544 is 4454861657893.

The square root of 3987561684544 is 1996888.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 3104503041600 + 883058642944 = 1761960^2 + 939712^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 271569427 + ... + 271584109.

Almost surely, 2^{3987561684544} is an apocalyptic number.

3987561684544 is a gapful number since it is divisible by the number (34) formed by its first and last digit.

3987561684544 is the 1996888-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3987561684544

3987561684544 is an abundant number, since it is smaller than the sum of its proper divisors (4418668405553).

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

3987561684544 is an frugal number, since it uses more digits than its factorization.

3987561684544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29412 (or 14702 counting only the distinct ones).

The product of its digits is 696729600, while the sum is 70.

The spelling of 3987561684544 in words is "three trillion, nine hundred eighty-seven billion, five hundred sixty-one million, six hundred eighty-four thousand, five hundred forty-four".