21000020220021 has 8 divisors (see below), whose sum is σ = 28013560089120. Its totient is φ = 13993246915472.

The previous prime is 21000020219963. The next prime is 21000020220059. The reversal of 21000020220021 is 12002202000012.

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 21000020220021 - 2¹⁴ = 21000020203637 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21000020219979 and 21000020220006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000020220121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1691633895 + ... + 1691646308.

It is an arithmetic number, because the mean of its divisors is an integer number (3501695011140).

Almost surely, 2^{21000020220021} is an apocalyptic number.

It is an amenable number.

21000020220021 is a deficient number, since it is larger than the sum of its proper divisors (7013539869099).

21000020220021 is a wasteful number, since it uses less digits than its factorization.

21000020220021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3383282275.

The product of its (nonzero) digits is 32, while the sum is 12.

Adding to 21000020220021 its reverse (12002202000012), we get a palindrome (33002222220033).

The spelling of 21000020220021 in words is "twenty-one trillion, twenty million, two hundred twenty thousand, twenty-one".