20404011220221 has 4 divisors (see below), whose sum is σ = 27205348293632. Its totient is φ = 13602674146812.

The previous prime is 20404011220207. The next prime is 20404011220259. The reversal of 20404011220221 is 12202211040402.

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 not a de Polignac number, because 20404011220221 - 2⁷ = 20404011220093 is a prime.

It is a super-2 number, since 2×20404011220221² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20404011220921) 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, 3400668536701 + ... + 3400668536706.

It is an arithmetic number, because the mean of its divisors is an integer number (6801337073408).

Almost surely, 2^{20404011220221} is an apocalyptic number.

It is an amenable number.

20404011220221 is a deficient number, since it is larger than the sum of its proper divisors (6801337073411).

20404011220221 is an equidigital number, since it uses as much as digits as its factorization.

20404011220221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6801337073410.

The product of its (nonzero) digits is 512, while the sum is 21.

Adding to 20404011220221 its reverse (12202211040402), we get a palindrome (32606222260623).

The spelling of 20404011220221 in words is "twenty trillion, four hundred four billion, eleven million, two hundred twenty thousand, two hundred twenty-one".