10211210021 has 4 divisors (see below), whose sum is σ = 10811869452.
Its totient is φ = 9610550592.
The previous prime is 10211210003. The next prime is 10211210027. The reversal of 10211210021 is 12001211201.
Adding to 10211210021 its reverse (12001211201), we get a palindrome (22212421222).
It is a semiprime because it is the product of two primes.
It can be written as a sum of positive squares in 2 ways, for example, as 2933413921 + 7277796100 = 54161^2 + 85310^2
It is a cyclic number.
It is not a de Polignac number, because 10211210021 - 222 = 10207015717 is a prime.
It is a Duffinian number.
It is a junction number, because it is equal to n+sod(n) for n = 10211209984 and 10211210011.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (10211210027) 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, 300329690 + ... + 300329723.
It is an arithmetic number, because the mean of its divisors is an integer number (2702967363).
Almost surely, 210211210021 is an apocalyptic number.
It is an amenable number.
10211210021 is a deficient number, since it is larger than the sum of its proper divisors (600659431).
10211210021 is an equidigital number, since it uses as much as digits as its factorization.
10211210021 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 600659430.
The product of its (nonzero) digits is 8, while the sum is 11.
The spelling of 10211210021 in words is "ten billion, two hundred eleven million, two hundred ten thousand, twenty-one".