399919968 has 216 divisors, whose sum is σ = 1401610392. Its totient is φ = 107476992.

The previous prime is 399919967. The next prime is 399919973. The reversal of 399919968 is 869919993.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399919963) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 239071 + ... + 240737.

It is an arithmetic number, because the mean of its divisors is an integer number (6488937).

Almost surely, 2^399919968 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 399919968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (700805196).

399919968 is an abundant number, since it is smaller than the sum of its proper divisors (1001690424).

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

399919968 is a wasteful number, since it uses less digits than its factorization.

399919968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1714 (or 1696 counting only the distinct ones).

The product of its digits is 8503056, while the sum is 63.

The square root of 399919968 is about 19997.9990999100. Note that the first 3 decimals coincide. The cubic root of 399919968 is about 736.7571563822.

The spelling of 399919968 in words is "three hundred ninety-nine million, nine hundred nineteen thousand, nine hundred sixty-eight".