390440 has 32 divisors (see below), whose sum is σ = 902880. Its totient is φ = 151872.

The previous prime is 390437. The next prime is 390449. The reversal of 390440 is 44093.

390440 = T₄₉ + T₅₀ + ... + T₁₃₄.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (390449) 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, 1607 + ... + 1833.

It is an arithmetic number, because the mean of its divisors is an integer number (28215).

2³⁹⁰⁴⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 390440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (451440).

390440 is an abundant number, since it is smaller than the sum of its proper divisors (512440).

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

390440 is a wasteful number, since it uses less digits than its factorization.

390440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281 (or 277 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 390440 is about 624.8519824726. The cubic root of 390440 is about 73.0889015097.

The spelling of 390440 in words is "three hundred ninety thousand, four hundred forty".