21012200100021 has 8 divisors (see below), whose sum is σ = 30171364246240. Its totient is φ = 12930584676912.

The previous prime is 21012200100007. The next prime is 21012200100041. The reversal of 21012200100021 is 12000100221012.

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

It is not a de Polignac number, because 21012200100021 - 2¹⁵ = 21012200067253 is a prime.

It is a super-3 number, since 3×21012200100021³ (a number of 41 digits) contains 333 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 (21012200100041) 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, 269387180731 + ... + 269387180808.

It is an arithmetic number, because the mean of its divisors is an integer number (3771420530780).

Almost surely, 2^{21012200100021} is an apocalyptic number.

It is an amenable number.

21012200100021 is a deficient number, since it is larger than the sum of its proper divisors (9159164146219).

21012200100021 is a wasteful number, since it uses less digits than its factorization.

21012200100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 538774361555.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21012200100021 its reverse (12000100221012), we get a palindrome (33012300321033).

The spelling of 21012200100021 in words is "twenty-one trillion, twelve billion, two hundred million, one hundred thousand, twenty-one".