390021 has 8 divisors (see below), whose sum is σ = 538080. Its totient is φ = 250992.

The previous prime is 390001. The next prime is 390043. The reversal of 390021 is 120093.

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

It is not a de Polignac number, because 390021 - 2⁵ = 389989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (390001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2155 + ... + 2328.

It is an arithmetic number, because the mean of its divisors is an integer number (67260).

2³⁹⁰⁰²¹ is an apocalyptic number.

It is an amenable number.

390021 is a deficient number, since it is larger than the sum of its proper divisors (148059).

390021 is a wasteful number, since it uses less digits than its factorization.

390021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4515.

The product of its (nonzero) digits is 54, while the sum is 15.

The square root of 390021 is about 624.5166130697. The cubic root of 390021 is about 73.0627470762.

The spelling of 390021 in words is "three hundred ninety thousand, twenty-one".