3991988016016 has 405 divisors, whose sum is σ = 10730292750513. Its totient is φ = 1432802891520.

The previous prime is 3991988015987. The next prime is 3991988016019. The reversal of 3991988016016 is 6106108891993.

The square root of 3991988016016 is 1997996.

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., 590530771600 + 3401457244416 = 768460^2 + 1844304^2 .

It is not an unprimeable number, because it can be changed into a prime (3991988016019) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 7999975735 + ... + 7999976233.

Almost surely, 2^{3991988016016} is an apocalyptic number.

3991988016016 is the 1997996-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3991988016016

3991988016016 is an abundant number, since it is smaller than the sum of its proper divisors (6738304734497).

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

3991988016016 is a wasteful number, since it uses less digits than its factorization.

3991988016016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1068 (or 532 counting only the distinct ones).

The product of its (nonzero) digits is 5038848, while the sum is 61.

The spelling of 3991988016016 in words is "three trillion, nine hundred ninety-one billion, nine hundred eighty-eight million, sixteen thousand, sixteen".