399999426 has 32 divisors (see below), whose sum is σ = 850409280. Its totient is φ = 124993536.

The previous prime is 399999421. The next prime is 399999433. The reversal of 399999426 is 624999993.

It is a self number, because there is not a number n which added to its sum of digits gives 399999426.

It is not an unprimeable number, because it can be changed into a prime (399999421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18585 + ... + 33843.

It is an arithmetic number, because the mean of its divisors is an integer number (26575290).

Almost surely, 2^399999426 is an apocalyptic number.

399999426 is an abundant number, since it is smaller than the sum of its proper divisors (450409854).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

399999426 is a wasteful number, since it uses less digits than its factorization.

399999426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15538.

The product of its digits is 8503056, while the sum is 60.

The square root of 399999426 is about 19999.9856499949. The cubic root of 399999426 is about 736.8059472889.

The spelling of 399999426 in words is "three hundred ninety-nine million, nine hundred ninety-nine thousand, four hundred twenty-six".