3991631544 has 48 divisors (see below), whose sum is σ = 10816533000. Its totient is φ = 1329822144.

The previous prime is 3991631519. The next prime is 3991631591. The reversal of 3991631544 is 4451361993.

3991631544 is a `hidden beast` number, since 3 + 9 + 9 + 1 + 631 + 5 + 4 + 4 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 3991631544.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 128007 + ... + 156105.

Almost surely, 2^3991631544 is an apocalyptic number.

It is an amenable number.

3991631544 is an abundant number, since it is smaller than the sum of its proper divisors (6824901456).

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

3991631544 is a wasteful number, since it uses less digits than its factorization.

3991631544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30084 (or 30077 counting only the distinct ones).

The product of its digits is 349920, while the sum is 45.

The square root of 3991631544 is about 63179.3601107197. The cubic root of 3991631544 is about 1586.2932710859.

The spelling of 3991631544 in words is "three billion, nine hundred ninety-one million, six hundred thirty-one thousand, five hundred forty-four".