21101221202122 has 8 divisors (see below), whose sum is σ = 31651855014276. Its totient is φ = 10550602864032.

The previous prime is 21101221202059. The next prime is 21101221202129. The reversal of 21101221202122 is 22120212210112.

It can be written as a sum of positive squares in 2 ways, for example, as 17336072922921 + 3765148279201 = 4163661^2 + 1940399^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21101221202122.

It is not an unprimeable number, because it can be changed into a prime (21101221202129) 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, 549918 + ... + 6519574.

Almost surely, 2^{21101221202122} is an apocalyptic number.

21101221202122 is a deficient number, since it is larger than the sum of its proper divisors (10550633812154).

21101221202122 is a wasteful number, since it uses less digits than its factorization.

21101221202122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7737032.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21101221202122 its reverse (22120212210112), we get a palindrome (43221433412234).

The spelling of 21101221202122 in words is "twenty-one trillion, one hundred one billion, two hundred twenty-one million, two hundred two thousand, one hundred twenty-two".