21021213000 has 64 divisors (see below), whose sum is σ = 65586193920. Its totient is φ = 5605656000.

The previous prime is 21021212987. The next prime is 21021213001. The reversal of 21021213000 is 31212012.

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 (21021213001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3500536 + ... + 3506535.

It is an arithmetic number, because the mean of its divisors is an integer number (1024784280).

Almost surely, 2^21021213000 is an apocalyptic number.

21021213000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21021213000 is an abundant number, since it is smaller than the sum of its proper divisors (44564980920).

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

21021213000 is a wasteful number, since it uses less digits than its factorization.

21021213000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7007095 (or 7007081 counting only the distinct ones).

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

Adding to 21021213000 its reverse (31212012), we get a palindrome (21052425012).

The spelling of 21021213000 in words is "twenty-one billion, twenty-one million, two hundred thirteen thousand".