399391822 has 4 divisors (see below), whose sum is σ = 599087736. Its totient is φ = 199695910.

The previous prime is 399391819. The next prime is 399391831. The reversal of 399391822 is 228193993.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 228193993 = 2917 ⋅78229.

It is a congruent 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 as a sum of consecutive naturals, namely, 99847954 + ... + 99847957.

It is an arithmetic number, because the mean of its divisors is an integer number (149771934).

Almost surely, 2^399391822 is an apocalyptic number.

399391822 is a deficient number, since it is larger than the sum of its proper divisors (199695914).

399391822 is a wasteful number, since it uses less digits than its factorization.

399391822 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199695913.

The product of its digits is 209952, while the sum is 46.

The square root of 399391822 is about 19984.7897662197. The cubic root of 399391822 is about 736.4326858261.

The spelling of 399391822 in words is "three hundred ninety-nine million, three hundred ninety-one thousand, eight hundred twenty-two".