428626421 has 2 divisors, whose sum is σ = 428626422. Its totient is φ = 428626420.

The previous prime is 428626379. The next prime is 428626433. The reversal of 428626421 is 124626824.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 428283025 + 343396 = 20695^2 + 586^2 .

It is a cyclic number.

It is not a de Polignac number, because 428626421 - 2²⁶ = 361517557 is a prime.

It is a Sophie Germain 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 (428626481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 214313210 + 214313211.

It is an arithmetic number, because the mean of its divisors is an integer number (214313211).

Almost surely, 2^428626421 is an apocalyptic number.

It is an amenable number.

428626421 is a deficient number, since it is larger than the sum of its proper divisors (1).

428626421 is an equidigital number, since it uses as much as digits as its factorization.

428626421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36864, while the sum is 35.

The square root of 428626421 is about 20703.2949310007. The cubic root of 428626421 is about 753.9796875061.

The spelling of 428626421 in words is "four hundred twenty-eight million, six hundred twenty-six thousand, four hundred twenty-one".