7858125409 has 2 divisors, whose sum is σ = 7858125410. Its totient is φ = 7858125408.

The previous prime is 7858125403. The next prime is 7858125413. The reversal of 7858125409 is 9045218587.

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., 7245414400 + 612711009 = 85120^2 + 24753^2 .

It is an emirp because it is prime and its reverse (9045218587) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7858125409 - 2⁵ = 7858125377 is a prime.

It is not a weakly prime, because it can be changed into another prime (7858125403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3929062704 + 3929062705.

It is an arithmetic number, because the mean of its divisors is an integer number (3929062705).

Almost surely, 2^7858125409 is an apocalyptic number.

It is an amenable number.

7858125409 is a deficient number, since it is larger than the sum of its proper divisors (1).

7858125409 is an equidigital number, since it uses as much as digits as its factorization.

7858125409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 806400, while the sum is 49.

The square root of 7858125409 is about 88646.0682094812. The cubic root of 7858125409 is about 1988.1065303048.

The spelling of 7858125409 in words is "seven billion, eight hundred fifty-eight million, one hundred twenty-five thousand, four hundred nine".