399619673 has 4 divisors (see below), whose sum is σ = 399923508. Its totient is φ = 399315840.

The previous prime is 399619669. The next prime is 399619679. The reversal of 399619673 is 376916993.

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 379977049 + 19642624 = 19493^2 + 4432^2 .

It is a cyclic number.

It is not a de Polignac number, because 399619673 - 2² = 399619669 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399619679) 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, 149936 + ... + 152577.

It is an arithmetic number, because the mean of its divisors is an integer number (99980877).

Almost surely, 2^399619673 is an apocalyptic number.

It is an amenable number.

399619673 is a deficient number, since it is larger than the sum of its proper divisors (303835).

399619673 is a wasteful number, since it uses less digits than its factorization.

399619673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 303834.

The product of its digits is 1653372, while the sum is 53.

The square root of 399619673 is about 19990.4895637901. The cubic root of 399619673 is about 736.5727029018.

The spelling of 399619673 in words is "three hundred ninety-nine million, six hundred nineteen thousand, six hundred seventy-three".