21301221000 has 128 divisors (see below), whose sum is σ = 70369378560. Its totient is φ = 5346176000.

The previous prime is 21301220959. The next prime is 21301221001. The reversal of 21301221000 is 12210312.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is not an unprimeable number, because it can be changed into a prime (21301221001) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 157836 + ... + 259835.

It is an arithmetic number, because the mean of its divisors is an integer number (549760770).

Almost surely, 2^21301221000 is an apocalyptic number.

21301221000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21301221000 is an abundant number, since it is smaller than the sum of its proper divisors (49068157560).

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

21301221000 is a wasteful number, since it uses less digits than its factorization.

21301221000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 417712 (or 417698 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 21301221000 its reverse (12210312), we get a palindrome (21313431312).

The spelling of 21301221000 in words is "twenty-one billion, three hundred one million, two hundred twenty-one thousand".