395799721 has 4 divisors (see below), whose sum is σ = 396323332. Its totient is φ = 395276112.

The previous prime is 395799683. The next prime is 395799731. The reversal of 395799721 is 127997593.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 206324496 + 189475225 = 14364^2 + 13765^2 .

It is a cyclic number.

It is not a de Polignac number, because 395799721 - 2¹⁷ = 395668649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (395799731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 260670 + ... + 262183.

It is an arithmetic number, because the mean of its divisors is an integer number (99080833).

Almost surely, 2^395799721 is an apocalyptic number.

It is an amenable number.

395799721 is a deficient number, since it is larger than the sum of its proper divisors (523611).

395799721 is an equidigital number, since it uses as much as digits as its factorization.

395799721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 523610.

The product of its digits is 1071630, while the sum is 52.

The square root of 395799721 is about 19894.7159064914. The cubic root of 395799721 is about 734.2182262622.

The spelling of 395799721 in words is "three hundred ninety-five million, seven hundred ninety-nine thousand, seven hundred twenty-one".