399660 has 24 divisors (see below), whose sum is σ = 1119216. Its totient is φ = 106560.

The previous prime is 399647. The next prime is 399667. The reversal of 399660 is 66993.

399660 = 220² + 221² + ... + 227².

It is not an unprimeable number, because it can be changed into a prime (399667) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3271 + ... + 3390.

It is an arithmetic number, because the mean of its divisors is an integer number (46634).

2³⁹⁹⁶⁶⁰ is an apocalyptic number.

399660 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

399660 is an abundant number, since it is smaller than the sum of its proper divisors (719556).

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

399660 is a wasteful number, since it uses less digits than its factorization.

399660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6673 (or 6671 counting only the distinct ones).

The product of its (nonzero) digits is 8748, while the sum is 33.

The square root of 399660 is about 632.1866812896. The cubic root of 399660 is about 73.6597478766.

The spelling of 399660 in words is "three hundred ninety-nine thousand, six hundred sixty".