428138549 has 2 divisors, whose sum is σ = 428138550. Its totient is φ = 428138548.

The previous prime is 428138539. The next prime is 428138561. The reversal of 428138549 is 945831824.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 378886225 + 49252324 = 19465^2 + 7018^2 .

It is a cyclic number.

It is not a de Polignac number, because 428138549 - 2²⁴ = 411361333 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (428138539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 214069274 + 214069275.

It is an arithmetic number, because the mean of its divisors is an integer number (214069275).

Almost surely, 2^428138549 is an apocalyptic number.

It is an amenable number.

428138549 is a deficient number, since it is larger than the sum of its proper divisors (1).

428138549 is an equidigital number, since it uses as much as digits as its factorization.

428138549 is an evil number, because the sum of its binary digits is even.

The product of its digits is 276480, while the sum is 44.

The square root of 428138549 is about 20691.5091039779. The cubic root of 428138549 is about 753.6935134925.

The spelling of 428138549 in words is "four hundred twenty-eight million, one hundred thirty-eight thousand, five hundred forty-nine".