21323121000 has 64 divisors (see below), whose sum is σ = 66528146880. Its totient is φ = 5686164800.

The previous prime is 21323120993. The next prime is 21323121011. The reversal of 21323121000 is 12132312.

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

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 15 ways as a sum of consecutive naturals, for example, 3550854 + ... + 3556853.

It is an arithmetic number, because the mean of its divisors is an integer number (1039502295).

Almost surely, 2^21323121000 is an apocalyptic number.

21323121000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21323121000 is an abundant number, since it is smaller than the sum of its proper divisors (45205025880).

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

21323121000 is a wasteful number, since it uses less digits than its factorization.

21323121000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7107731 (or 7107717 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21323121000 its reverse (12132312), we get a palindrome (21335253312).

It can be divided in two parts, 2132312 and 1000, that added together give a palindrome (2133312).

The spelling of 21323121000 in words is "twenty-one billion, three hundred twenty-three million, one hundred twenty-one thousand".