20918538080 has 144 divisors (see below), whose sum is σ = 57517477920. Its totient is φ = 7159173120.

The previous prime is 20918538073. The next prime is 20918538103. The reversal of 20918538080 is 8083581902.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 297341 + ... + 360899.

It is an arithmetic number, because the mean of its divisors is an integer number (399426930).

Almost surely, 2^20918538080 is an apocalyptic number.

20918538080 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 20918538080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28758738960).

20918538080 is an abundant number, since it is smaller than the sum of its proper divisors (36598939840).

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

20918538080 is a wasteful number, since it uses less digits than its factorization.

20918538080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63613 (or 63594 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 44.

The spelling of 20918538080 in words is "twenty billion, nine hundred eighteen million, five hundred thirty-eight thousand, eighty".