21100221000 has 96 divisors (see below), whose sum is σ = 71318777400. Its totient is φ = 5626723200.

The previous prime is 21100220971. The next prime is 21100221011. The reversal of 21100221000 is 12200112.

It can be written as a sum of positive squares in 4 ways, for example, as 8004165156 + 13096055844 = 89466^2 + 114438^2 .

It is a Harshad number since it is a multiple of its sum of digits (9).

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 23 ways as a sum of consecutive naturals, for example, 1163235 + ... + 1181234.

Almost surely, 2^21100221000 is an apocalyptic number.

21100221000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21100221000 is an abundant number, since it is smaller than the sum of its proper divisors (50218556400).

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

21100221000 is a wasteful number, since it uses less digits than its factorization.

21100221000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2344496 (or 2344479 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 21100221000 its reverse (12200112), we get a palindrome (21112421112).

The spelling of 21100221000 in words is "twenty-one billion, one hundred million, two hundred twenty-one thousand".