221110101010021 has 4 divisors (see below), whose sum is σ = 221110130769292. Its totient is φ = 221110071250752.

The previous prime is 221110101010013. The next prime is 221110101010103. The reversal of 221110101010021 is 120010101011122.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 195811605292900 + 25298495717121 = 13993270^2 + 5029761^2 .

It is a cyclic number.

It is not a de Polignac number, because 221110101010021 - 2³ = 221110101010013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221110101009983 and 221110101010010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221110101010621) 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, 6627271 + ... + 22048603.

It is an arithmetic number, because the mean of its divisors is an integer number (55277532692323).

Almost surely, 2^{221110101010021} is an apocalyptic number.

It is an amenable number.

221110101010021 is a deficient number, since it is larger than the sum of its proper divisors (29759271).

221110101010021 is a wasteful number, since it uses less digits than its factorization.

221110101010021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29759270.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 221110101010021 its reverse (120010101011122), we get a palindrome (341120202021143).

The spelling of 221110101010021 in words is "two hundred twenty-one trillion, one hundred ten billion, one hundred one million, ten thousand, twenty-one".