305990 has 16 divisors (see below), whose sum is σ = 566352. Its totient is φ = 118944.

The previous prime is 305971. The next prime is 305999. The reversal of 305990 is 99503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (305999) by changing a digit.

305990 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 7 ways as a sum of consecutive naturals, for example, 44 + ... + 783.

It is an arithmetic number, because the mean of its divisors is an integer number (35397).

2³⁰⁵⁹⁹⁰ is an apocalyptic number.

305990 is a deficient number, since it is larger than the sum of its proper divisors (260362).

305990 is a wasteful number, since it uses less digits than its factorization.

305990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 871.

The product of its (nonzero) digits is 1215, while the sum is 26.

The square root of 305990 is about 553.1636285947. The cubic root of 305990 is about 67.3859069408.

It can be divided in two parts, 30 and 5990, that multiplied together give a triangular number (179700 = T₅₉₉).

The spelling of 305990 in words is "three hundred five thousand, nine hundred ninety".