399999994 has 8 divisors (see below), whose sum is σ = 600809760. Its totient is φ = 199730076.

The previous prime is 399999959. The next prime is 400000009. The reversal of 399999994 is 499999993.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 133104 + ... + 136075.

It is an arithmetic number, because the mean of its divisors is an integer number (75101220).

Almost surely, 2^399999994 is an apocalyptic number.

399999994 is a deficient number, since it is larger than the sum of its proper divisors (200809766).

399999994 is a wasteful number, since it uses less digits than its factorization.

399999994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 269924.

The product of its digits is 57395628, while the sum is 70.

The square root of 399999994 is about 19999.9998500000. Note that the first 3 decimals coincide. The cubic root of 399999994 is about 736.8062960440.

Subtracting 399999994 from its reverse (499999993), we obtain a palindrome (99999999).

The spelling of 399999994 in words is "three hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred ninety-four".