428947681 has 2 divisors, whose sum is σ = 428947682. Its totient is φ = 428947680.

The previous prime is 428947657. The next prime is 428947691. The reversal of 428947681 is 186749824.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 256288081 + 172659600 = 16009^2 + 13140^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-428947681 is a prime.

It is a super-2 number, since 2×428947681² = 367992226070555522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (428947691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 214473840 + 214473841.

It is an arithmetic number, because the mean of its divisors is an integer number (214473841).

Almost surely, 2^428947681 is an apocalyptic number.

It is an amenable number.

428947681 is a deficient number, since it is larger than the sum of its proper divisors (1).

428947681 is an equidigital number, since it uses as much as digits as its factorization.

428947681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 774144, while the sum is 49.

The square root of 428947681 is about 20711.0521461369. The cubic root of 428947681 is about 754.1680123592.

The spelling of 428947681 in words is "four hundred twenty-eight million, nine hundred forty-seven thousand, six hundred eighty-one".