20115105280 has 120 divisors (see below), whose sum is σ = 49954874112. Its totient is φ = 7767760896.

The previous prime is 20115105277. The next prime is 20115105323. The reversal of 20115105280 is 8250151102.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2148289 + ... + 2157631.

Almost surely, 2^20115105280 is an apocalyptic number.

20115105280 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 20115105280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24977437056).

20115105280 is an abundant number, since it is smaller than the sum of its proper divisors (29839768832).

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

20115105280 is an frugal number, since it uses more digits than its factorization.

20115105280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9424 (or 9379 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 25.

Adding to 20115105280 its reverse (8250151102), we get a palindrome (28365256382).

The spelling of 20115105280 in words is "twenty billion, one hundred fifteen million, one hundred five thousand, two hundred eighty".