428913441221 has 2 divisors, whose sum is σ = 428913441222. Its totient is φ = 428913441220.

The previous prime is 428913441197. The next prime is 428913441223. The reversal of 428913441221 is 122144319824.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 341675320900 + 87238120321 = 584530^2 + 295361^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-428913441221 is a prime.

It is a Sophie Germain prime.

Together with 428913441223, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (428913441223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 214456720610 + 214456720611.

It is an arithmetic number, because the mean of its divisors is an integer number (214456720611).

Almost surely, 2^428913441221 is an apocalyptic number.

It is an amenable number.

428913441221 is a deficient number, since it is larger than the sum of its proper divisors (1).

428913441221 is an equidigital number, since it uses as much as digits as its factorization.

428913441221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 110592, while the sum is 41.

The spelling of 428913441221 in words is "four hundred twenty-eight billion, nine hundred thirteen million, four hundred forty-one thousand, two hundred twenty-one".