399239280 has 240 divisors, whose sum is σ = 1517652864. Its totient is φ = 96733440.

The previous prime is 399239279. The next prime is 399239311. The reversal of 399239280 is 82932993.

399239280 is a `hidden beast` number, since 399 + 239 + 28 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 212907 + ... + 214773.

Almost surely, 2^399239280 is an apocalyptic number.

399239280 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 399239280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (758826432).

399239280 is an abundant number, since it is smaller than the sum of its proper divisors (1118413584).

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

399239280 is a wasteful number, since it uses less digits than its factorization.

399239280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1906 (or 1888 counting only the distinct ones).

The product of its (nonzero) digits is 209952, while the sum is 45.

The square root of 399239280 is about 19980.9729492835. The cubic root of 399239280 is about 736.3389172398.

The spelling of 399239280 in words is "three hundred ninety-nine million, two hundred thirty-nine thousand, two hundred eighty".