21818153280 has 896 divisors, whose sum is σ = 92613943296. Its totient is φ = 4217241600.

The previous prime is 21818153267. The next prime is 21818153297. The reversal of 21818153280 is 8235181812.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 69706404 + ... + 69706716.

It is an arithmetic number, because the mean of its divisors is an integer number (103363776).

Almost surely, 2^21818153280 is an apocalyptic number.

21818153280 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 21818153280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46306971648).

21818153280 is an abundant number, since it is smaller than the sum of its proper divisors (70795790016).

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

21818153280 is a wasteful number, since it uses less digits than its factorization.

21818153280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 415 (or 405 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 39.

It can be divided in two parts, 2181815 and 3280, that added together give a triangular number (2185095 = T₂₀₉₀).

The spelling of 21818153280 in words is "twenty-one billion, eight hundred eighteen million, one hundred fifty-three thousand, two hundred eighty".