428811221 has 4 divisors (see below), whose sum is σ = 437934912. Its totient is φ = 419687532.

The previous prime is 428811217. The next prime is 428811239. The reversal of 428811221 is 122118824.

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 428811221 - 2² = 428811217 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 (428811821) 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, 4561775 + ... + 4561868.

It is an arithmetic number, because the mean of its divisors is an integer number (109483728).

Almost surely, 2^428811221 is an apocalyptic number.

It is an amenable number.

428811221 is a deficient number, since it is larger than the sum of its proper divisors (9123691).

428811221 is an equidigital number, since it uses as much as digits as its factorization.

428811221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9123690.

The product of its digits is 2048, while the sum is 29.

The square root of 428811221 is about 20707.7575077554. The cubic root of 428811221 is about 754.0880300469.

The spelling of 428811221 in words is "four hundred twenty-eight million, eight hundred eleven thousand, two hundred twenty-one".