345990 has 32 divisors (see below), whose sum is σ = 875520. Its totient is φ = 87264.

The previous prime is 345979. The next prime is 345997. The reversal of 345990 is 99543.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (345997) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 267 + ... + 873.

It is an arithmetic number, because the mean of its divisors is an integer number (27360).

2³⁴⁵⁹⁹⁰ is an apocalyptic number.

345990 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 345990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (437760).

345990 is an abundant number, since it is smaller than the sum of its proper divisors (529530).

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

345990 is a wasteful number, since it uses less digits than its factorization.

345990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 636.

The product of its (nonzero) digits is 4860, while the sum is 30.

The square root of 345990 is about 588.2091464777. The cubic root of 345990 is about 70.2028131761.

The spelling of 345990 in words is "three hundred forty-five thousand, nine hundred ninety".