21818465280 has 264 divisors, whose sum is σ = 76351003872. Its totient is φ = 5760516096.

The previous prime is 21818465269. The next prime is 21818465293. The reversal of 21818465280 is 8256481812.

21818465280 is a `hidden beast` number, since 2 + 1 + 81 + 8 + 46 + 528 + 0 = 666.

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

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, 4743942 + ... + 4748538.

It is an arithmetic number, because the mean of its divisors is an integer number (289208348).

Almost surely, 2^21818465280 is an apocalyptic number.

21818465280 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 21818465280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38175501936).

21818465280 is an abundant number, since it is smaller than the sum of its proper divisors (54532538592).

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

21818465280 is a wasteful number, since it uses less digits than its factorization.

21818465280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4731 (or 4710 counting only the distinct ones).

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

The spelling of 21818465280 in words is "twenty-one billion, eight hundred eighteen million, four hundred sixty-five thousand, two hundred eighty".