20021210101 has 4 divisors (see below), whose sum is σ = 20021493100. Its totient is φ = 20020927104.

The previous prime is 20021210087. The next prime is 20021210147. The reversal of 20021210101 is 10101212002.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 18164031076 + 1857179025 = 134774^2 + 43095^2 .

It is a cyclic number.

It is not a de Polignac number, because 20021210101 - 2¹⁹ = 20020685813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021210401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 69445 + ... + 211813.

It is an arithmetic number, because the mean of its divisors is an integer number (5005373275).

Almost surely, 2^20021210101 is an apocalyptic number.

It is an amenable number.

20021210101 is a deficient number, since it is larger than the sum of its proper divisors (282999).

20021210101 is a wasteful number, since it uses less digits than its factorization.

20021210101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 282998.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 20021210101 its reverse (10101212002), we get a palindrome (30122422103).

The spelling of 20021210101 in words is "twenty billion, twenty-one million, two hundred ten thousand, one hundred one".