30861 has 12 divisors (see below), whose sum is σ = 46592. Its totient is φ = 20412.

The previous prime is 30859. The next prime is 30869. The reversal of 30861 is 16803.

30861 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 30861 - 2¹ = 30859 is a prime.

It is a Duffinian number.

It is a Curzon number.

30861 is a lucky number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30869) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 180 + ... + 306.

2³⁰⁸⁶¹ is an apocalyptic number.

It is an amenable number.

30861 is a deficient number, since it is larger than the sum of its proper divisors (15731).

30861 is an equidigital number, since it uses as much as digits as its factorization.

30861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142 (or 130 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 30861 is about 175.6729916635. The cubic root of 30861 is about 31.3667843549.

The spelling of 30861 in words is "thirty thousand, eight hundred sixty-one".