399976220 has 72 divisors (see below), whose sum is σ = 1028558160. Its totient is φ = 129911040.

The previous prime is 399976219. The next prime is 399976231. The reversal of 399976220 is 22679993.

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 in 23 ways as a sum of consecutive naturals, for example, 7880 + ... + 29360.

It is an arithmetic number, because the mean of its divisors is an integer number (14285530).

Almost surely, 2^399976220 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 399976220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (514279080).

399976220 is an abundant number, since it is smaller than the sum of its proper divisors (628581940).

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

399976220 is a wasteful number, since it uses less digits than its factorization.

399976220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21523 (or 21514 counting only the distinct ones).

The product of its (nonzero) digits is 367416, while the sum is 47.

The square root of 399976220 is about 19999.4054911640. The cubic root of 399976220 is about 736.7916983939.

The spelling of 399976220 in words is "three hundred ninety-nine million, nine hundred seventy-six thousand, two hundred twenty".