399520144 has 45 divisors (see below), whose sum is σ = 820073163. Its totient is φ = 188526816.

The previous prime is 399520141. The next prime is 399520151. The reversal of 399520144 is 441025993.

The square root of 399520144 is 19988.

It is a perfect power (a square), and thus also a powerful number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399520141) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1518957 + ... + 1519219.

Almost surely, 2^399520144 is an apocalyptic number.

399520144 is the 19988-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 399520144

399520144 is an abundant number, since it is smaller than the sum of its proper divisors (420553019).

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

399520144 is an equidigital number, since it uses as much as digits as its factorization.

399520144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 572 (or 284 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 37.

The cubic root of 399520144 is about 736.5115477281.

The spelling of 399520144 in words is "three hundred ninety-nine million, five hundred twenty thousand, one hundred forty-four".