8420222221 has 4 divisors (see below), whose sum is σ = 8427538944. Its totient is φ = 8412905500.

The previous prime is 8420222197. The next prime is 8420222227. The reversal of 8420222221 is 1222220248.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 8420222221 - 2⁹ = 8420221709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8420222227) 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, 3656635 + ... + 3658936.

It is an arithmetic number, because the mean of its divisors is an integer number (2106884736).

Almost surely, 2^8420222221 is an apocalyptic number.

It is an amenable number.

8420222221 is a deficient number, since it is larger than the sum of its proper divisors (7316723).

8420222221 is a wasteful number, since it uses less digits than its factorization.

8420222221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7316722.

The product of its (nonzero) digits is 2048, while the sum is 25.

The square root of 8420222221 is about 91761.7688419311. The cubic root of 8420222221 is about 2034.4226596609.

Adding to 8420222221 its reverse (1222220248), we get a palindrome (9642442469).

The spelling of 8420222221 in words is "eight billion, four hundred twenty million, two hundred twenty-two thousand, two hundred twenty-one".