399497797 has 4 divisors (see below), whose sum is σ = 400068396. Its totient is φ = 398927200.

The previous prime is 399497783. The next prime is 399497801. The reversal of 399497797 is 797794993.

It is a happy number.

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 270470916 + 129026881 = 16446^2 + 11359^2 .

It is a cyclic number.

It is not a de Polignac number, because 399497797 - 2⁷ = 399497669 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399497737) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 284248 + ... + 285649.

It is an arithmetic number, because the mean of its divisors is an integer number (100017099).

Almost surely, 2^399497797 is an apocalyptic number.

It is an amenable number.

399497797 is a deficient number, since it is larger than the sum of its proper divisors (570599).

399497797 is an equidigital number, since it uses as much as digits as its factorization.

399497797 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 570598.

The product of its digits is 27005076, while the sum is 64.

The square root of 399497797 is about 19987.4409817765. The cubic root of 399497797 is about 736.4978153121.

The spelling of 399497797 in words is "three hundred ninety-nine million, four hundred ninety-seven thousand, seven hundred ninety-seven".