428526781 has 2 divisors, whose sum is σ = 428526782. Its totient is φ = 428526780.

The previous prime is 428526767. The next prime is 428526797. The reversal of 428526781 is 187625824.

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., 271425625 + 157101156 = 16475^2 + 12534^2 .

It is a cyclic number.

It is not a de Polignac number, because 428526781 - 2⁷ = 428526653 is a prime.

It is a super-2 number, since 2×428526781² = 367270404068443922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (428526751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 214263390 + 214263391.

It is an arithmetic number, because the mean of its divisors is an integer number (214263391).

Almost surely, 2^428526781 is an apocalyptic number.

It is an amenable number.

428526781 is a deficient number, since it is larger than the sum of its proper divisors (1).

428526781 is an equidigital number, since it uses as much as digits as its factorization.

428526781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 215040, while the sum is 43.

The square root of 428526781 is about 20700.8884108871. Note that the first 3 decimals coincide. The cubic root of 428526781 is about 753.9212587249.

The spelling of 428526781 in words is "four hundred twenty-eight million, five hundred twenty-six thousand, seven hundred eighty-one".