3999636655272 has 96 divisors (see below), whose sum is σ = 11244061701600. Its totient is φ = 1331964368064.

The previous prime is 3999636655253. The next prime is 3999636655307. The reversal of 3999636655272 is 2725566369993.

3999636655272 is a `hidden beast` number, since 3 + 9 + 9 + 9 + 6 + 3 + 66 + 552 + 7 + 2 = 666.

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

It is a self number, because there is not a number n which added to its sum of digits gives 3999636655272.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1115823 + ... + 3040449.

It is an arithmetic number, because the mean of its divisors is an integer number (117125642725).

Almost surely, 2^{3999636655272} 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 3999636655272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5622030850800).

3999636655272 is an abundant number, since it is smaller than the sum of its proper divisors (7244425046328).

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

3999636655272 is a wasteful number, since it uses less digits than its factorization.

3999636655272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1925717 (or 1925701 counting only the distinct ones).

The product of its digits is 992023200, while the sum is 72.

The spelling of 3999636655272 in words is "three trillion, nine hundred ninety-nine billion, six hundred thirty-six million, six hundred fifty-five thousand, two hundred seventy-two".