3971639628 has 108 divisors (see below), whose sum is σ = 11444112680. Its totient is φ = 1203491520.

The previous prime is 3971639627. The next prime is 3971639629. The reversal of 3971639628 is 8269361793.

3971639628 is a `hidden beast` number, since 3 + 9 + 7 + 1 + 6 + 3 + 9 + 628 = 666.

It is an interprime number because it is at equal distance from previous prime (3971639627) and next prime (3971639629).

It is a tau number, because it is divible by the number of its divisors (108).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (3971639627) by changing a digit.

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 35 ways as a sum of consecutive naturals, for example, 100728 + ... + 134496.

Almost surely, 2^3971639628 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 3971639628, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5722056340).

3971639628 is an abundant number, since it is smaller than the sum of its proper divisors (7472473052).

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

3971639628 is a wasteful number, since it uses less digits than its factorization.

3971639628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33810 (or 33785 counting only the distinct ones).

The product of its digits is 2939328, while the sum is 54.

The square root of 3971639628 is about 63020.9459465661. The cubic root of 3971639628 is about 1583.6405434348.

The spelling of 3971639628 in words is "three billion, nine hundred seventy-one million, six hundred thirty-nine thousand, six hundred twenty-eight".