7821428569 has 2 divisors, whose sum is σ = 7821428570. Its totient is φ = 7821428568.

The previous prime is 7821428521. The next prime is 7821428597. The reversal of 7821428569 is 9658241287.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7715338569 + 106090000 = 87837^2 + 10300^2 .

It is a cyclic number.

It is not a de Polignac number, because 7821428569 - 2⁹ = 7821428057 is a prime.

It is a super-2 number, since 2×7821428569² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (7821429569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3910714284 + 3910714285.

It is an arithmetic number, because the mean of its divisors is an integer number (3910714285).

Almost surely, 2^7821428569 is an apocalyptic number.

It is an amenable number.

7821428569 is a deficient number, since it is larger than the sum of its proper divisors (1).

7821428569 is an equidigital number, since it uses as much as digits as its factorization.

7821428569 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1935360, while the sum is 52.

The square root of 7821428569 is about 88438.8408393054. The cubic root of 7821428569 is about 1985.0069322364.

The spelling of 7821428569 in words is "seven billion, eight hundred twenty-one million, four hundred twenty-eight thousand, five hundred sixty-nine".