20219808728 has 16 divisors (see below), whose sum is σ = 43328161680. Its totient is φ = 8665632288.

The previous prime is 20219808727. The next prime is 20219808779. The reversal of 20219808728 is 82780891202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20219808727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 180533951 + ... + 180534062.

It is an arithmetic number, because the mean of its divisors is an integer number (2708010105).

Almost surely, 2^20219808728 is an apocalyptic number.

20219808728 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

20219808728 is an abundant number, since it is smaller than the sum of its proper divisors (23108352952).

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

20219808728 is a wasteful number, since it uses less digits than its factorization.

20219808728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 361068026 (or 361068022 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 47.

The spelling of 20219808728 in words is "twenty billion, two hundred nineteen million, eight hundred eight thousand, seven hundred twenty-eight".