21655460000 has 120 divisors (see below), whose sum is σ = 55114248420. Its totient is φ = 8363264000.

The previous prime is 21655459999. The next prime is 21655460023. The reversal of 21655460000 is 6455612.

It can be written as a sum of positive squares in 10 ways, for example, as 765960976 + 20889499024 = 27676^2 + 144532^2 .

It is a Harshad number since it is a multiple of its sum of digits (29).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 561332 + ... + 598668.

Almost surely, 2^21655460000 is an apocalyptic number.

21655460000 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 21655460000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27557124210).

21655460000 is an abundant number, since it is smaller than the sum of its proper divisors (33458788420).

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

21655460000 is an equidigital number, since it uses as much as digits as its factorization.

21655460000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37396 (or 37373 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 29.

The spelling of 21655460000 in words is "twenty-one billion, six hundred fifty-five million, four hundred sixty thousand".