20504897280 has 720 divisors, whose sum is σ = 88324346880. Its totient is φ = 4437172224.

The previous prime is 20504897251. The next prime is 20504897323. The reversal of 20504897280 is 8279840502.

20504897280 is a `hidden beast` number, since 20 + 5 + 0 + 489 + 72 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

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 polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 13788697 + ... + 13790183.

It is an arithmetic number, because the mean of its divisors is an integer number (122672704).

Almost surely, 2^20504897280 is an apocalyptic number.

20504897280 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 20504897280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44162173440).

20504897280 is an abundant number, since it is smaller than the sum of its proper divisors (67819449600).

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

20504897280 is a wasteful number, since it uses less digits than its factorization.

20504897280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1546 (or 1523 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 45.

The spelling of 20504897280 in words is "twenty billion, five hundred four million, eight hundred ninety-seven thousand, two hundred eighty".