399987823 has 8 divisors (see below), whose sum is σ = 418119680. Its totient is φ = 382182840.

The previous prime is 399987821. The next prime is 399987859. The reversal of 399987823 is 328789993.

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

It is a cyclic number.

It is not a de Polignac number, because 399987823 - 2¹ = 399987821 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 (399987821) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 79215 + ... + 84112.

It is an arithmetic number, because the mean of its divisors is an integer number (52264960).

Almost surely, 2^399987823 is an apocalyptic number.

399987823 is a deficient number, since it is larger than the sum of its proper divisors (18131857).

399987823 is a wasteful number, since it uses less digits than its factorization.

399987823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163437.

The product of its digits is 5878656, while the sum is 58.

The square root of 399987823 is about 19999.6955726831. The cubic root of 399987823 is about 736.7988229103.

The spelling of 399987823 in words is "three hundred ninety-nine million, nine hundred eighty-seven thousand, eight hundred twenty-three".