21012102122021 has 8 divisors (see below), whose sum is σ = 21150046663200. Its totient is φ = 20874587986000.

The previous prime is 21012102121981. The next prime is 21012102122029. The reversal of 21012102122021 is 12022120121012.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21012102122021 is a prime.

It is a super-2 number, since 2×21012102122021² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012102122029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 107503331 + ... + 107698608.

It is an arithmetic number, because the mean of its divisors is an integer number (2643755832900).

Almost surely, 2^{21012102122021} is an apocalyptic number.

It is an amenable number.

21012102122021 is a deficient number, since it is larger than the sum of its proper divisors (137944541179).

21012102122021 is a wasteful number, since it uses less digits than its factorization.

21012102122021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215202579.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21012102122021 its reverse (12022120121012), we get a palindrome (33034222243033).

The spelling of 21012102122021 in words is "twenty-one trillion, twelve billion, one hundred two million, one hundred twenty-two thousand, twenty-one".