20110001210021 has 4 divisors (see below), whose sum is σ = 20110010623212. Its totient is φ = 20109991796832.

The previous prime is 20110001210017. The next prime is 20110001210051. The reversal of 20110001210021 is 12001210001102.

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 15870973177921 + 4239028032100 = 3983839^2 + 2058890^2 .

It is a cyclic number.

It is not a de Polignac number, because 20110001210021 - 2² = 20110001210017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20110001209984 and 20110001210011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20110001210051) 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, 209801 + ... + 6345393.

It is an arithmetic number, because the mean of its divisors is an integer number (5027502655803).

Almost surely, 2^{20110001210021} is an apocalyptic number.

It is an amenable number.

20110001210021 is a deficient number, since it is larger than the sum of its proper divisors (9413191).

20110001210021 is an equidigital number, since it uses as much as digits as its factorization.

20110001210021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9413190.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 20110001210021 its reverse (12001210001102), we get a palindrome (32111211211123).

The spelling of 20110001210021 in words is "twenty trillion, one hundred ten billion, one million, two hundred ten thousand, twenty-one".