399820544 has 36 divisors (see below), whose sum is σ = 801624096. Its totient is φ = 199022592.

The previous prime is 399820543. The next prime is 399820601. The reversal of 399820544 is 445028993.

It is a junction number, because it is equal to n+sod(n) for n = 399820495 and 399820504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399820541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56297 + ... + 62999.

It is an arithmetic number, because the mean of its divisors is an integer number (22267336).

Almost surely, 2^399820544 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 399820544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (400812048).

399820544 is an abundant number, since it is smaller than the sum of its proper divisors (401803552).

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

399820544 is an equidigital number, since it uses as much as digits as its factorization.

399820544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6952 (or 6938 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 44.

The square root of 399820544 is about 19995.5130966925. The cubic root of 399820544 is about 736.6960963198.

It can be divided in two parts, 3998 and 20544, that added together give a palindrome (24542).

The spelling of 399820544 in words is "three hundred ninety-nine million, eight hundred twenty thousand, five hundred forty-four".