20722504428 has 84 divisors (see below), whose sum is σ = 54435334800. Its totient is φ = 6899419296.

The previous prime is 20722504391. The next prime is 20722504447. The reversal of 20722504428 is 82440522702.

20722504428 is a `hidden beast` number, since 2 + 0 + 7 + 225 + 0 + 4 + 428 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 20722504392 and 20722504401.

It is an unprimeable number.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 2816098 + ... + 2823446.

It is an arithmetic number, because the mean of its divisors is an integer number (648039700).

Almost surely, 2^20722504428 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20722504428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27217667400).

20722504428 is an abundant number, since it is smaller than the sum of its proper divisors (33712830372).

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

20722504428 is an equidigital number, since it uses as much as digits as its factorization.

20722504428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8338 (or 8321 counting only the distinct ones).

The product of its (nonzero) digits is 71680, while the sum is 36.

The spelling of 20722504428 in words is "twenty billion, seven hundred twenty-two million, five hundred four thousand, four hundred twenty-eight".