21020021220122 has 4 divisors (see below), whose sum is σ = 31530031830186. Its totient is φ = 10510010610060.

The previous prime is 21020021220083. The next prime is 21020021220151. The reversal of 21020021220122 is 22102212002012.

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 only one way, i.e., 20894123278081 + 125897942041 = 4571009^2 + 354821^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21020021220122.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5255005305029 + ... + 5255005305032.

Almost surely, 2^{21020021220122} is an apocalyptic number.

21020021220122 is a deficient number, since it is larger than the sum of its proper divisors (10510010610064).

21020021220122 is a wasteful number, since it uses less digits than its factorization.

21020021220122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10510010610063.

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

Adding to 21020021220122 its reverse (22102212002012), we get a palindrome (43122233222134).

The spelling of 21020021220122 in words is "twenty-one trillion, twenty billion, twenty-one million, two hundred twenty thousand, one hundred twenty-two".