390689 has 8 divisors (see below), whose sum is σ = 431592. Its totient is φ = 351360.

The previous prime is 390673. The next prime is 390703. The reversal of 390689 is 986093.

It can be written as a sum of positive squares in 4 ways, for example, as 21025 + 369664 = 145^2 + 608^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 390689 - 2⁴ = 390673 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (390289) 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, 167 + ... + 899.

It is an arithmetic number, because the mean of its divisors is an integer number (53949).

2³⁹⁰⁶⁸⁹ is an apocalyptic number.

It is an amenable number.

390689 is a deficient number, since it is larger than the sum of its proper divisors (40903).

390689 is a wasteful number, since it uses less digits than its factorization.

390689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 787.

The product of its (nonzero) digits is 11664, while the sum is 35.

The square root of 390689 is about 625.0511979030. The cubic root of 390689 is about 73.1044354962.

The spelling of 390689 in words is "three hundred ninety thousand, six hundred eighty-nine".