20728086625 has 16 divisors (see below), whose sum is σ = 25876103760. Its totient is φ = 16577692800.

The previous prime is 20728086619. The next prime is 20728086637. The reversal of 20728086625 is 52668082702.

It can be written as a sum of positive squares in 8 ways, for example, as 5910380641 + 14817705984 = 76879^2 + 121728^2 .

It is not a de Polignac number, because 20728086625 - 2¹⁹ = 20727562337 is a prime.

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, 449127 + ... + 493123.

It is an arithmetic number, because the mean of its divisors is an integer number (1617256485).

Almost surely, 2^20728086625 is an apocalyptic number.

20728086625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20728086625 is a deficient number, since it is larger than the sum of its proper divisors (5148017135).

20728086625 is an equidigital number, since it uses as much as digits as its factorization.

20728086625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47781 (or 47771 counting only the distinct ones).

The product of its (nonzero) digits is 645120, while the sum is 46.

The spelling of 20728086625 in words is "twenty billion, seven hundred twenty-eight million, eighty-six thousand, six hundred twenty-five".