20120210021 has 4 divisors (see below), whose sum is σ = 20120519232. Its totient is φ = 20119900812.

The previous prime is 20120210009. The next prime is 20120210029. The reversal of 20120210021 is 12001202102.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20120210021 - 2⁶ = 20120209957 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20120209984 and 20120210011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20120210029) 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, 14951 + ... + 201156.

It is an arithmetic number, because the mean of its divisors is an integer number (5030129808).

Almost surely, 2^20120210021 is an apocalyptic number.

It is an amenable number.

20120210021 is a deficient number, since it is larger than the sum of its proper divisors (309211).

20120210021 is an equidigital number, since it uses as much as digits as its factorization.

20120210021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309210.

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

Adding to 20120210021 its reverse (12001202102), we get a palindrome (32121412123).

The spelling of 20120210021 in words is "twenty billion, one hundred twenty million, two hundred ten thousand, twenty-one".