7211728728 has 64 divisors (see below), whose sum is σ = 20279944800. Its totient is φ = 2403903744.

The previous prime is 7211728723. The next prime is 7211728747. The reversal of 7211728728 is 8278271127.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7211728723) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 188601 + ... + 223592.

Almost surely, 2^7211728728 is an apocalyptic number.

It is an amenable number.

7211728728 is an abundant number, since it is smaller than the sum of its proper divisors (13068216072).

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

7211728728 is an equidigital number, since it uses as much as digits as its factorization.

7211728728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 412220 (or 412198 counting only the distinct ones).

The product of its digits is 175616, while the sum is 45.

The square root of 7211728728 is about 84921.8978120485. The cubic root of 7211728728 is about 1932.0267154209.

The spelling of 7211728728 in words is "seven billion, two hundred eleven million, seven hundred twenty-eight thousand, seven hundred twenty-eight".