20419 has 4 divisors (see below), whose sum is σ = 23344. Its totient is φ = 17496.
The previous prime is 20411. The next prime is 20431. The reversal of 20419 is 91402.
It is a semiprime because it is the product of two primes.
It is a 7-Lehmer number, since φ(20419) divides (20419-1)7.
It is a cyclic number.
It is not a de Polignac number, because 20419 - 23 = 20411 is a prime.
It is a super-2 number, since 2×204192 = 833871122, which contains 22 as substring.
It is an Ulam number.
It is a Duffinian number.
It is a nialpdrome in base 12.
It is not an unprimeable number, because it can be changed into a prime (20411) 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, 1452 + ... + 1465.
It is an arithmetic number, because the mean of its divisors is an integer number (5836).
220419 is an apocalyptic number.
20419 is the 83-rd hex number.
20419 is a deficient number, since it is larger than the sum of its proper divisors (2925).
20419 is an equidigital number, since it uses as much as digits as its factorization.
20419 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 2924.
The product of its (nonzero) digits is 72, while the sum is 16.
The square root of 20419 is about 142.8950663949. The cubic root of 20419 is about 27.3324244526.
The spelling of 20419 in words is "twenty thousand, four hundred nineteen".
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