21221010002021 has 16 divisors (see below), whose sum is σ = 21506884883568. Its totient is φ = 20936638272000.

The previous prime is 21221010002011. The next prime is 21221010002053. The reversal of 21221010002021 is 12020001012212.

It can be written as a sum of positive squares in 8 ways, for example, as 468384196996 + 20752625805025 = 684386^2 + 4555505^2 .

It is a cyclic number.

It is not a de Polignac number, because 21221010002021 - 2²² = 21221005807717 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21221010001987 and 21221010002005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221010002011) 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, 271062335 + ... + 271140611.

It is an arithmetic number, because the mean of its divisors is an integer number (1344180305223).

Almost surely, 2^{21221010002021} is an apocalyptic number.

It is an amenable number.

21221010002021 is a deficient number, since it is larger than the sum of its proper divisors (285874881547).

21221010002021 is a wasteful number, since it uses less digits than its factorization.

21221010002021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87832.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21221010002021 its reverse (12020001012212), we get a palindrome (33241011014233).

The spelling of 21221010002021 in words is "twenty-one trillion, two hundred twenty-one billion, ten million, two thousand, twenty-one".