21221232000 has 128 divisors (see below), whose sum is σ = 70348543200. Its totient is φ = 5658982400.

The previous prime is 21221231963. The next prime is 21221232023. The reversal of 21221232000 is 23212212.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 173055 + ... + 269054.

Almost surely, 2^21221232000 is an apocalyptic number.

21221232000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221232000 is an abundant number, since it is smaller than the sum of its proper divisors (49127311200).

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

21221232000 is an equidigital number, since it uses as much as digits as its factorization.

21221232000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 442141 (or 442119 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

Adding to 21221232000 its reverse (23212212), we get a palindrome (21244444212).

The spelling of 21221232000 in words is "twenty-one billion, two hundred twenty-one million, two hundred thirty-two thousand".