21210102021 has 8 divisors (see below), whose sum is σ = 29768564320. Its totient is φ = 13395853872.

The previous prime is 21210102019. The next prime is 21210102061. The reversal of 21210102021 is 12020101212.

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

It is not a de Polignac number, because 21210102021 - 2¹ = 21210102019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21210101988 and 21210102006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210102061) 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, 186053470 + ... + 186053583.

It is an arithmetic number, because the mean of its divisors is an integer number (3721070540).

Almost surely, 2^21210102021 is an apocalyptic number.

It is an amenable number.

21210102021 is a deficient number, since it is larger than the sum of its proper divisors (8558462299).

21210102021 is a wasteful number, since it uses less digits than its factorization.

21210102021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 372107075.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21210102021 its reverse (12020101212), we get a palindrome (33230203233).

The spelling of 21210102021 in words is "twenty-one billion, two hundred ten million, one hundred two thousand, twenty-one".