20728673280 has 704 divisors, whose sum is σ = 87031234560. Its totient is φ = 4578508800.

The previous prime is 20728673263. The next prime is 20728673297. The reversal of 20728673280 is 8237682702.

20728673280 is a `hidden beast` number, since 20 + 7 + 286 + 73 + 280 = 666.

It is an interprime number because it is at equal distance from previous prime (20728673263) and next prime (20728673297).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 29997735 + ... + 29998425.

Almost surely, 2^20728673280 is an apocalyptic number.

20728673280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20728673280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43515617280).

20728673280 is an abundant number, since it is smaller than the sum of its proper divisors (66302561280).

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

20728673280 is a wasteful number, since it uses less digits than its factorization.

20728673280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 763 (or 739 counting only the distinct ones).

The product of its (nonzero) digits is 451584, while the sum is 45.

The spelling of 20728673280 in words is "twenty billion, seven hundred twenty-eight million, six hundred seventy-three thousand, two hundred eighty".