21021100012 has 24 divisors (see below), whose sum is σ = 40175513280. Its totient is φ = 9544492560.

The previous prime is 21021099991. The next prime is 21021100019. The reversal of 21021100012 is 21000112012.

It is not an unprimeable number, because it can be changed into a prime (21021100019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 223462 + ... + 303277.

It is an arithmetic number, because the mean of its divisors is an integer number (1673979720).

Almost surely, 2^21021100012 is an apocalyptic number.

21021100012 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21021100012 is a deficient number, since it is larger than the sum of its proper divisors (19154413268).

21021100012 is a wasteful number, since it uses less digits than its factorization.

21021100012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 527661 (or 527659 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21021100012 its reverse (21000112012), we get a palindrome (42021212024).

The spelling of 21021100012 in words is "twenty-one billion, twenty-one million, one hundred thousand, twelve".