20808506880 has 640 divisors, whose sum is σ = 87444403200. Its totient is φ = 4589125632.

The previous prime is 20808506879. The next prime is 20808506881. The reversal of 20808506880 is 8860580802.

It is an interprime number because it is at equal distance from previous prime (20808506879) and next prime (20808506881).

It is a tau number, because it is divible by the number of its divisors (640).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20808506881) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 14030619 + ... + 14032101.

It is an arithmetic number, because the mean of its divisors is an integer number (136631880).

Almost surely, 2^20808506880 is an apocalyptic number.

20808506880 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 20808506880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43722201600).

20808506880 is an abundant number, since it is smaller than the sum of its proper divisors (66635896320).

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

20808506880 is a wasteful number, since it uses less digits than its factorization.

20808506880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1551 (or 1529 counting only the distinct ones).

The product of its (nonzero) digits is 245760, while the sum is 45.

The spelling of 20808506880 in words is "twenty billion, eight hundred eight million, five hundred six thousand, eight hundred eighty".