7723728021 has 16 divisors (see below), whose sum is σ = 10666186560. Its totient is φ = 4971547952.

The previous prime is 7723728017. The next prime is 7723728091. The reversal of 7723728021 is 1208273277.

It is not a de Polignac number, because 7723728021 - 2² = 7723728017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7723728091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20386 + ... + 125948.

It is an arithmetic number, because the mean of its divisors is an integer number (666636660).

Almost surely, 2^7723728021 is an apocalyptic number.

It is an amenable number.

7723728021 is a deficient number, since it is larger than the sum of its proper divisors (2942458539).

7723728021 is an equidigital number, since it uses as much as digits as its factorization.

7723728021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105653 (or 105595 counting only the distinct ones).

The product of its (nonzero) digits is 65856, while the sum is 39.

The square root of 7723728021 is about 87884.7428226311. The cubic root of 7723728021 is about 1976.7071088409.

The spelling of 7723728021 in words is "seven billion, seven hundred twenty-three million, seven hundred twenty-eight thousand, twenty-one".