21355220000 has 60 divisors (see below), whose sum is σ = 52537093686. Its totient is φ = 8542080000.

The previous prime is 21355219909. The next prime is 21355220017. The reversal of 21355220000 is 2255312.

It can be written as a sum of positive squares in 5 ways, for example, as 49730704 + 21305489296 = 7052^2 + 145964^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 513881 + ... + 553880.

Almost surely, 2^21355220000 is an apocalyptic number.

21355220000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21355220000 is an abundant number, since it is smaller than the sum of its proper divisors (31181873686).

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

21355220000 is an equidigital number, since it uses as much as digits as its factorization.

21355220000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1067791 (or 1067768 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 20.

Adding to 21355220000 its reverse (2255312), we get a palindrome (21357475312).

The spelling of 21355220000 in words is "twenty-one billion, three hundred fifty-five million, two hundred twenty thousand".