399120065 has 4 divisors (see below), whose sum is σ = 478944084. Its totient is φ = 319296048.

The previous prime is 399120053. The next prime is 399120079. The reversal of 399120065 is 560021993.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 560021993 = 41 ⋅13659073.

It can be written as a sum of positive squares in 2 ways, for example, as 101626561 + 297493504 = 10081^2 + 17248^2 .

It is a cyclic number.

It is not a de Polignac number, because 399120065 - 2¹⁴ = 399103681 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39912002 + ... + 39912011.

It is an arithmetic number, because the mean of its divisors is an integer number (119736021).

Almost surely, 2^399120065 is an apocalyptic number.

It is an amenable number.

399120065 is a deficient number, since it is larger than the sum of its proper divisors (79824019).

399120065 is an equidigital number, since it uses as much as digits as its factorization.

399120065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79824018.

The product of its (nonzero) digits is 14580, while the sum is 35.

The square root of 399120065 is about 19977.9895134621. The cubic root of 399120065 is about 736.2656183542.

The spelling of 399120065 in words is "three hundred ninety-nine million, one hundred twenty thousand, sixty-five".