221000221021 has 4 divisors (see below), whose sum is σ = 221068921852. Its totient is φ = 220931520192.

The previous prime is 221000220979. The next prime is 221000221027. The reversal of 221000221021 is 120122000122.

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 106478216100 + 114522004921 = 326310^2 + 338411^2 .

It is a cyclic number.

It is not a de Polignac number, because 221000221021 - 2³⁷ = 83561267549 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221000220992 and 221000221010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221000221027) 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, 34345590 + ... + 34352023.

It is an arithmetic number, because the mean of its divisors is an integer number (55267230463).

Almost surely, 2^221000221021 is an apocalyptic number.

It is an amenable number.

221000221021 is a deficient number, since it is larger than the sum of its proper divisors (68700831).

221000221021 is an equidigital number, since it uses as much as digits as its factorization.

221000221021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68700830.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 221000221021 its reverse (120122000122), we get a palindrome (341122221143).

The spelling of 221000221021 in words is "two hundred twenty-one billion, two hundred twenty-one thousand, twenty-one".