21012211210021 has 8 divisors (see below), whose sum is σ = 22140990006080. Its totient is φ = 19885719708288.

The previous prime is 21012211210019. The next prime is 21012211210037. The reversal of 21012211210021 is 12001211221012.

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

It is not a de Polignac number, because 21012211210021 - 2¹ = 21012211210019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21012211209977 and 21012211210004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012211210321) 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, 571804716 + ... + 571841461.

It is an arithmetic number, because the mean of its divisors is an integer number (2767623750760).

Almost surely, 2^{21012211210021} is an apocalyptic number.

It is an amenable number.

21012211210021 is a deficient number, since it is larger than the sum of its proper divisors (1128778796059).

21012211210021 is a wasteful number, since it uses less digits than its factorization.

21012211210021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1143647163.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21012211210021 its reverse (12001211221012), we get a palindrome (33013422431033).

The spelling of 21012211210021 in words is "twenty-one trillion, twelve billion, two hundred eleven million, two hundred ten thousand, twenty-one".