20519 has 6 divisors (see below), whose sum is σ = 22104. Its totient is φ = 19040.

The previous prime is 20509. The next prime is 20521. The reversal of 20519 is 91502.

It is a de Polignac number, because none of the positive numbers 2^k-20519 is a prime.

It is a super-2 number, since 2×20519² = 842058722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a plaindrome in base 6.

It is a junction number, because it is equal to n+sod(n) for n = 20497 and 20506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20509) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 254 + ... + 324.

It is an arithmetic number, because the mean of its divisors is an integer number (3684).

2²⁰⁵¹⁹ is an apocalyptic number.

20519 is a deficient number, since it is larger than the sum of its proper divisors (1585).

20519 is an equidigital number, since it uses as much as digits as its factorization.

20519 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105 (or 88 counting only the distinct ones).

The product of its (nonzero) digits is 90, while the sum is 17.

The square root of 20519 is about 143.2445461440. The cubic root of 20519 is about 27.3769710777.

Subtracting from 20519 its sum of digits (17), we obtain a palindrome (20502).

The spelling of 20519 in words is "twenty thousand, five hundred nineteen".