6420125728 has 12 divisors (see below), whose sum is σ = 12639622590. Its totient is φ = 3210062848.

The previous prime is 6420125689. The next prime is 6420125731. The reversal of 6420125728 is 8275210246.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 5680938384 + 739187344 = 75372^2 + 27188^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100314433 + ... + 100314496.

Almost surely, 2^6420125728 is an apocalyptic number.

It is an amenable number.

6420125728 is a deficient number, since it is larger than the sum of its proper divisors (6219496862).

6420125728 is a wasteful number, since it uses less digits than its factorization.

6420125728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200628939 (or 200628931 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 37.

The square root of 6420125728 is about 80125.6870672570. The cubic root of 6420125728 is about 1858.5796502303.

The spelling of 6420125728 in words is "six billion, four hundred twenty million, one hundred twenty-five thousand, seven hundred twenty-eight".