20919 has 8 divisors (see below), whose sum is σ = 29440. Its totient is φ = 13176.

The previous prime is 20903. The next prime is 20921. The reversal of 20919 is 91902.

It is a happy number.

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

It is not a de Polignac number, because 20919 - 2⁴ = 20903 is a prime.

It is a super-2 number, since 2×20919² = 875209122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20895 and 20904.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20929) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 127 + ... + 240.

It is an arithmetic number, because the mean of its divisors is an integer number (3680).

2²⁰⁹¹⁹ is an apocalyptic number.

20919 is a deficient number, since it is larger than the sum of its proper divisors (8521).

20919 is a wasteful number, since it uses less digits than its factorization.

20919 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 389.

The product of its (nonzero) digits is 162, while the sum is 21.

The square root of 20919 is about 144.6340208941. The cubic root of 20919 is about 27.5537241769.

It can be divided in two parts, 20 and 919, that added together give a palindrome (939).

The spelling of 20919 in words is "twenty thousand, nine hundred nineteen".