21212000010021 has 16 divisors (see below), whose sum is σ = 29778825036800. Its totient is φ = 13393634009328.

The previous prime is 21212000010013. The next prime is 21212000010029. The reversal of 21212000010021 is 12001000021212.

It is an interprime number because it is at equal distance from previous prime (21212000010013) and next prime (21212000010029).

It is not a de Polignac number, because 21212000010021 - 2³ = 21212000010013 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21212000009979 and 21212000010006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212000010029) 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, 47255611 + ... + 47702376.

It is an arithmetic number, because the mean of its divisors is an integer number (1861176564800).

Almost surely, 2^{21212000010021} is an apocalyptic number.

It is an amenable number.

21212000010021 is a deficient number, since it is larger than the sum of its proper divisors (8566825026779).

21212000010021 is a wasteful number, since it uses less digits than its factorization.

21212000010021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94961928.

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

Adding to 21212000010021 its reverse (12001000021212), we get a palindrome (33213000031233).

The spelling of 21212000010021 in words is "twenty-one trillion, two hundred twelve billion, ten thousand, twenty-one".