399566340 has 36 divisors (see below), whose sum is σ = 1212018444. Its totient is φ = 106550976.

The previous prime is 399566339. The next prime is 399566353. The reversal of 399566340 is 43665993.

It is a happy number.

399566340 is a `hidden beast` number, since 3 + 9 + 9 + 5 + 6 + 634 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 250335684 + 149230656 = 15822^2 + 12216^2 .

It is a tau number, because it is divible by the number of its divisors (36).

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

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 1109727 + ... + 1110086.

It is an arithmetic number, because the mean of its divisors is an integer number (33667179).

Almost surely, 2^399566340 is an apocalyptic number.

399566340 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

399566340 is an abundant number, since it is smaller than the sum of its proper divisors (812452104).

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

399566340 is a wasteful number, since it uses less digits than its factorization.

399566340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2219828 (or 2219823 counting only the distinct ones).

The product of its (nonzero) digits is 524880, while the sum is 45.

The square root of 399566340 is about 19989.1555599530. The cubic root of 399566340 is about 736.5399339281.

The spelling of 399566340 in words is "three hundred ninety-nine million, five hundred sixty-six thousand, three hundred forty".