3129647728 has 40 divisors (see below), whose sum is σ = 6126951600. Its totient is φ = 1548572160.

The previous prime is 3129647713. The next prime is 3129647753. The reversal of 3129647728 is 8277469213.

It is a happy number.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 762963 + ... + 767053.

It is an arithmetic number, because the mean of its divisors is an integer number (153173790).

Almost surely, 2^3129647728 is an apocalyptic number.

It is an amenable number.

3129647728 is a deficient number, since it is larger than the sum of its proper divisors (2997303872).

3129647728 is a wasteful number, since it uses less digits than its factorization.

3129647728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4585 (or 4579 counting only the distinct ones).

The product of its digits is 1016064, while the sum is 49.

The square root of 3129647728 is about 55943.2545352878. The cubic root of 3129647728 is about 1462.7333121630.

The spelling of 3129647728 in words is "three billion, one hundred twenty-nine million, six hundred forty-seven thousand, seven hundred twenty-eight".