399309142 has 4 divisors (see below), whose sum is σ = 598963716. Its totient is φ = 199654570.

The previous prime is 399309121. The next prime is 399309151. The reversal of 399309142 is 241903993.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 241903993 = 29 ⋅8341517.

It is a junction number, because it is equal to n+sod(n) for n = 399309095 and 399309104.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99827284 + ... + 99827287.

It is an arithmetic number, because the mean of its divisors is an integer number (149740929).

Almost surely, 2^399309142 is an apocalyptic number.

399309142 is a deficient number, since it is larger than the sum of its proper divisors (199654574).

399309142 is a wasteful number, since it uses less digits than its factorization.

399309142 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199654573.

The product of its (nonzero) digits is 52488, while the sum is 40.

The square root of 399309142 is about 19982.7210859783. The cubic root of 399309142 is about 736.3818648418.

The spelling of 399309142 in words is "three hundred ninety-nine million, three hundred nine thousand, one hundred forty-two".