30905 has 8 divisors (see below), whose sum is σ = 42432. Its totient is φ = 21168.

The previous prime is 30893. The next prime is 30911. The reversal of 30905 is 50903.

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

It is not a de Polignac number, because 30905 - 2⁶ = 30841 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 407 + ... + 476.

It is an arithmetic number, because the mean of its divisors is an integer number (5304).

2³⁰⁹⁰⁵ is an apocalyptic number.

30905 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

30905 is a deficient number, since it is larger than the sum of its proper divisors (11527).

30905 is an equidigital number, since it uses as much as digits as its factorization.

30905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 895.

The product of its (nonzero) digits is 135, while the sum is 17.

The square root of 30905 is about 175.7981797403. The cubic root of 30905 is about 31.3816843163.

The spelling of 30905 in words is "thirty thousand, nine hundred five".