20001201011221 has 4 divisors (see below), whose sum is σ = 20002025929312. Its totient is φ = 20000376093132.

The previous prime is 20001201011219. The next prime is 20001201011237. The reversal of 20001201011221 is 12211010210002.

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 20001201011221 - 2¹ = 20001201011219 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 (20001201011021) 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, 412422675 + ... + 412471168.

It is an arithmetic number, because the mean of its divisors is an integer number (5000506482328).

Almost surely, 2^{20001201011221} is an apocalyptic number.

It is an amenable number.

20001201011221 is a deficient number, since it is larger than the sum of its proper divisors (824918091).

20001201011221 is an equidigital number, since it uses as much as digits as its factorization.

20001201011221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 824918090.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 20001201011221 its reverse (12211010210002), we get a palindrome (32212211221223).

The spelling of 20001201011221 in words is "twenty trillion, one billion, two hundred one million, eleven thousand, two hundred twenty-one".