19613 has 4 divisors (see below), whose sum is σ = 21408. Its totient is φ = 17820.

The previous prime is 19609. The next prime is 19661. The reversal of 19613 is 31691.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 19613 - 2² = 19609 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a plaindrome in base 7.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19603) 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, 881 + ... + 902.

It is an arithmetic number, because the mean of its divisors is an integer number (5352).

2¹⁹⁶¹³ is an apocalyptic number.

It is an amenable number.

19613 is a deficient number, since it is larger than the sum of its proper divisors (1795).

19613 is a wasteful number, since it uses less digits than its factorization.

19613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1794.

The product of its digits is 162, while the sum is 20.

The square root of 19613 is about 140.0464208754. The cubic root of 19613 is about 26.9679546656.

The spelling of 19613 in words is "nineteen thousand, six hundred thirteen".