21111221000021 has 8 divisors (see below), whose sum is σ = 22395797610624. Its totient is φ = 19831393287360.

The previous prime is 21111220999991. The next prime is 21111221000033. The reversal of 21111221000021 is 12000012211112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21111221000021 - 2³⁴ = 21094041130837 is a prime.

It is a super-2 number, since 2×21111221000021² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111221000071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1187215325 + ... + 1187233106.

It is an arithmetic number, because the mean of its divisors is an integer number (2799474701328).

Almost surely, 2^{21111221000021} is an apocalyptic number.

It is an amenable number.

21111221000021 is a deficient number, since it is larger than the sum of its proper divisors (1284576610603).

21111221000021 is a wasteful number, since it uses less digits than its factorization.

21111221000021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2374448971.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21111221000021 its reverse (12000012211112), we get a palindrome (33111233211133).

The spelling of 21111221000021 in words is "twenty-one trillion, one hundred eleven billion, two hundred twenty-one million, twenty-one", and thus it is an aban number.