20798457680 has 360 divisors, whose sum is σ = 66605877576. Its totient is φ = 5982197760.

The previous prime is 20798457677. The next prime is 20798457689. The reversal of 20798457680 is 8675489702.

It can be written as a sum of positive squares in 4 ways, for example, as 4223440144 + 16575017536 = 64988^2 + 128744^2 .

It is a Harshad number since it is a multiple of its sum of digits (56).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20798457689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 6164474 + ... + 6167846.

Almost surely, 2^20798457680 is an apocalyptic number.

20798457680 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 20798457680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33302938788).

20798457680 is an abundant number, since it is smaller than the sum of its proper divisors (45807419896).

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

20798457680 is a wasteful number, since it uses less digits than its factorization.

20798457680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3435 (or 3411 counting only the distinct ones).

The product of its (nonzero) digits is 6773760, while the sum is 56.

The spelling of 20798457680 in words is "twenty billion, seven hundred ninety-eight million, four hundred fifty-seven thousand, six hundred eighty".