221000202112021 has 4 divisors (see below), whose sum is σ = 223278554711212. Its totient is φ = 218721849512832.

The previous prime is 221000202112009. The next prime is 221000202112051. The reversal of 221000202112021 is 120211202000122.

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 33223580720100 + 187776621391921 = 5763990^2 + 13703161^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221000202112021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221000202111986 and 221000202112004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221000202112051) 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, 1139176299450 + ... + 1139176299643.

It is an arithmetic number, because the mean of its divisors is an integer number (55819638677803).

Almost surely, 2^{221000202112021} is an apocalyptic number.

It is an amenable number.

221000202112021 is a deficient number, since it is larger than the sum of its proper divisors (2278352599191).

221000202112021 is an equidigital number, since it uses as much as digits as its factorization.

221000202112021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2278352599190.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 221000202112021 its reverse (120211202000122), we get a palindrome (341211404112143).

The spelling of 221000202112021 in words is "two hundred twenty-one trillion, two hundred two million, one hundred twelve thousand, twenty-one".