390852809 has 2 divisors, whose sum is σ = 390852810. Its totient is φ = 390852808.

The previous prime is 390852767. The next prime is 390852811. The reversal of 390852809 is 908258093.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 370177600 + 20675209 = 19240^2 + 4547^2 .

It is a cyclic number.

It is not a de Polignac number, because 390852809 - 2²⁴ = 374075593 is a prime.

It is a super-3 number, since 3×390852809³ (a number of 27 digits) contains 333 as substring.

Together with 390852811, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 390852809.

It is not a weakly prime, because it can be changed into another prime (390852509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195426404 + 195426405.

It is an arithmetic number, because the mean of its divisors is an integer number (195426405).

Almost surely, 2^390852809 is an apocalyptic number.

It is an amenable number.

390852809 is a deficient number, since it is larger than the sum of its proper divisors (1).

390852809 is an equidigital number, since it uses as much as digits as its factorization.

390852809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 155520, while the sum is 44.

The square root of 390852809 is about 19769.9976985330. The cubic root of 390852809 is about 731.1465120162.

The spelling of 390852809 in words is "three hundred ninety million, eight hundred fifty-two thousand, eight hundred nine".