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30819 = 310273

30819 has 4 divisors (see below), whose sum is σ = 41096. Its totient is φ = 20544.

The previous prime is 30817. The next prime is 30829. The reversal of 30819 is 91803.

30819 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 30819 - 21 = 30817 is a prime.

It is a super-2 number, since 2×308192 = 1899621522, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 30795 and 30804.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 30819.

It is not an unprimeable number, because it can be changed into a prime (30817) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5134 + ... + 5139.

It is an arithmetic number, because the mean of its divisors is an integer number (10274).

230819 is an apocalyptic number.

30819 is a deficient number, since it is larger than the sum of its proper divisors (10277).

30819 is a wasteful number, since it uses less digits than its factorization.

30819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10276.

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 30819 is about 175.5534106761. The cubic root of 30819 is about 31.3525484473.

Subtracting from 30819 its product of nonzero digits (216), we obtain a palindrome (30603).

The spelling of 30819 in words is "thirty thousand, eight hundred nineteen".

Divisors: 1 3 10273 30819