390645 has 12 divisors (see below), whose sum is σ = 677196. Its totient is φ = 208320.

The previous prime is 390581. The next prime is 390647. The reversal of 390645 is 546093.

It is a happy number.

390645 is nontrivially palindromic in base 4 and base 16.

It can be written as a sum of positive squares in 2 ways, for example, as 236196 + 154449 = 486^2 + 393^2 .

It is not a de Polignac number, because 390645 - 2⁶ = 390581 is a prime.

390645 is an undulating number in base 16.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (390647) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4296 + ... + 4385.

It is an arithmetic number, because the mean of its divisors is an integer number (56433).

2³⁹⁰⁶⁴⁵ is an apocalyptic number.

It is an amenable number.

390645 is a deficient number, since it is larger than the sum of its proper divisors (286551).

390645 is a wasteful number, since it uses less digits than its factorization.

390645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8692 (or 8689 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 27.

The square root of 390645 is about 625.0159997952. The cubic root of 390645 is about 73.1016910149.

It can be divided in two parts, 390 and 645, that added together give a triangular number (1035 = T₄₅).

The spelling of 390645 in words is "three hundred ninety thousand, six hundred forty-five".