402390 has 48 divisors (see below), whose sum is σ = 1111968. Its totient is φ = 100608.

The previous prime is 402383. The next prime is 402403. The reversal of 402390 is 93204.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

402390 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1399 + ... + 1661.

It is an arithmetic number, because the mean of its divisors is an integer number (23166).

2⁴⁰²³⁹⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 402390, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (555984).

402390 is an abundant number, since it is smaller than the sum of its proper divisors (709578).

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

402390 is a wasteful number, since it uses less digits than its factorization.

402390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 293 (or 290 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

The square root of 402390 is about 634.3421789539. The cubic root of 402390 is about 73.8270859222.

Adding to 402390 its reverse (93204), we get a palindrome (495594).

The spelling of 402390 in words is "four hundred two thousand, three hundred ninety".