21200220021 has 8 divisors (see below), whose sum is σ = 28279437984. Its totient is φ = 14127241040.

The previous prime is 21200219987. The next prime is 21200220049. The reversal of 21200220021 is 12002200212.

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 21200220021 - 2¹⁰ = 21200218997 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21200219979 and 21200220006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200220421) 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, 1551810 + ... + 1565411.

It is an arithmetic number, because the mean of its divisors is an integer number (3534929748).

Almost surely, 2^21200220021 is an apocalyptic number.

It is an amenable number.

21200220021 is a deficient number, since it is larger than the sum of its proper divisors (7079217963).

21200220021 is a wasteful number, since it uses less digits than its factorization.

21200220021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3119491.

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

Adding to 21200220021 its reverse (12002200212), we get a palindrome (33202420233).

It can be divided in two parts, 2 and 1200220021, that multiplied together give a palindrome (2400440042).

The spelling of 21200220021 in words is "twenty-one billion, two hundred million, two hundred twenty thousand, twenty-one".