3129281680 has 80 divisors (see below), whose sum is σ = 8325967104. Its totient is φ = 1071475200.

The previous prime is 3129281671. The next prime is 3129281693. The reversal of 3129281680 is 861829213.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 474405 + ... + 480955.

Almost surely, 2^3129281680 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 3129281680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4162983552).

3129281680 is an abundant number, since it is smaller than the sum of its proper divisors (5196685424).

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

3129281680 is a wasteful number, since it uses less digits than its factorization.

3129281680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7424 (or 7418 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 40.

The square root of 3129281680 is about 55939.9828387532. The cubic root of 3129281680 is about 1462.6762821576.

The spelling of 3129281680 in words is "three billion, one hundred twenty-nine million, two hundred eighty-one thousand, six hundred eighty".