4020728643 has 24 divisors (see below), whose sum is σ = 6140144400. Its totient is φ = 2528293824.

The previous prime is 4020728639. The next prime is 4020728659. The reversal of 4020728643 is 3468270204.

4020728643 is a `hidden beast` number, since 4 + 0 + 2 + 0 + 7 + 2 + 8 + 643 = 666.

It is not a de Polignac number, because 4020728643 - 2² = 4020728639 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 4020728598 and 4020728607.

It is not an unprimeable number, because it can be changed into a prime (4020728843) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12180 + ... + 90497.

It is an arithmetic number, because the mean of its divisors is an integer number (255839350).

Almost surely, 2^4020728643 is an apocalyptic number.

4020728643 is a deficient number, since it is larger than the sum of its proper divisors (2119415757).

4020728643 is a wasteful number, since it uses less digits than its factorization.

4020728643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102931 (or 102928 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 36.

The square root of 4020728643 is about 63409.2157576484. The cubic root of 4020728643 is about 1590.1383847752.

Adding to 4020728643 its reverse (3468270204), we get a palindrome (7488998847).

The spelling of 4020728643 in words is "four billion, twenty million, seven hundred twenty-eight thousand, six hundred forty-three".