210102020021 has 16 divisors (see below), whose sum is σ = 215587951488. Its totient is φ = 204676056000.

The previous prime is 210102020003. The next prime is 210102020053. The reversal of 210102020021 is 120020201012.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-210102020021 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 210102019984 and 210102020011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210102028021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6189746 + ... + 6223596.

It is an arithmetic number, because the mean of its divisors is an integer number (13474246968).

Almost surely, 2^210102020021 is an apocalyptic number.

It is an amenable number.

210102020021 is a deficient number, since it is larger than the sum of its proper divisors (5485931467).

210102020021 is a wasteful number, since it uses less digits than its factorization.

210102020021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34732.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 210102020021 its reverse (120020201012), we get a palindrome (330122221033).

The spelling of 210102020021 in words is "two hundred ten billion, one hundred two million, twenty thousand, twenty-one".