21021110220122 has 4 divisors (see below), whose sum is σ = 31531665330186. Its totient is φ = 10510555110060.

The previous prime is 21021110220037. The next prime is 21021110220179. The reversal of 21021110220122 is 22102201112012.

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., 11789533420921 + 9231576799201 = 3433589^2 + 3038351^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21021110220122.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5255277555029 + ... + 5255277555032.

Almost surely, 2^{21021110220122} is an apocalyptic number.

21021110220122 is a deficient number, since it is larger than the sum of its proper divisors (10510555110064).

21021110220122 is a wasteful number, since it uses less digits than its factorization.

21021110220122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10510555110063.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21021110220122 its reverse (22102201112012), we get a palindrome (43123311332134).

The spelling of 21021110220122 in words is "twenty-one trillion, twenty-one billion, one hundred ten million, two hundred twenty thousand, one hundred twenty-two".