20100122220221 has 4 divisors (see below), whose sum is σ = 20235022369500. Its totient is φ = 19965222070944.

The previous prime is 20100122220203. The next prime is 20100122220247. The reversal of 20100122220221 is 12202222100102.

It is a happy number.

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 1055530212100 + 19044592008121 = 1027390^2 + 4364011^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20100122220221 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20100122220221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20100122225221) 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, 67450074416 + ... + 67450074713.

It is an arithmetic number, because the mean of its divisors is an integer number (5058755592375).

Almost surely, 2^{20100122220221} is an apocalyptic number.

It is an amenable number.

20100122220221 is a deficient number, since it is larger than the sum of its proper divisors (134900149279).

20100122220221 is a wasteful number, since it uses less digits than its factorization.

20100122220221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134900149278.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 20100122220221 its reverse (12202222100102), we get a palindrome (32302344320323).

The spelling of 20100122220221 in words is "twenty trillion, one hundred billion, one hundred twenty-two million, two hundred twenty thousand, two hundred twenty-one".