397904785 has 4 divisors (see below), whose sum is σ = 477485748. Its totient is φ = 318323824.

The previous prime is 397904743. The next prime is 397904813. The reversal of 397904785 is 587409793.

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 58018689 + 339886096 = 7617^2 + 18436^2 .

It is a cyclic number.

It is not a de Polignac number, because 397904785 - 2⁷ = 397904657 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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, 39790474 + ... + 39790483.

It is an arithmetic number, because the mean of its divisors is an integer number (119371437).

Almost surely, 2^397904785 is an apocalyptic number.

It is an amenable number.

397904785 is a deficient number, since it is larger than the sum of its proper divisors (79580963).

397904785 is an equidigital number, since it uses as much as digits as its factorization.

397904785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79580962.

The product of its (nonzero) digits is 1905120, while the sum is 52.

The square root of 397904785 is about 19947.5508521723. The cubic root of 397904785 is about 735.5175739613.

The spelling of 397904785 in words is "three hundred ninety-seven million, nine hundred four thousand, seven hundred eighty-five".