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BaseRepresentation
bin101000011101111
31001102101
411003233
51130334
6235531
7114256
oct50357
931371
1020719
1114626
12bba7
13957a
14779d
156214
hex50ef

20719 has 2 divisors, whose sum is σ = 20720. Its totient is φ = 20718.

The previous prime is 20717. The next prime is 20731. The reversal of 20719 is 91702.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20719 - 21 = 20717 is a prime.

It is a super-2 number, since 2×207192 = 858553922, which contains 22 as substring.

Together with 20717, it forms a pair of twin primes.

It is a Chen prime.

It is a plaindrome in base 14.

It is a nialpdrome in base 12.

It is a junction number, because it is equal to n+sod(n) for n = 20696 and 20705.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20717) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10359 + 10360.

It is an arithmetic number, because the mean of its divisors is an integer number (10360).

220719 is an apocalyptic number.

20719 is a deficient number, since it is larger than the sum of its proper divisors (1).

20719 is an equidigital number, since it uses as much as digits as its factorization.

20719 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 126, while the sum is 19.

The square root of 20719 is about 143.9409601191. The cubic root of 20719 is about 27.4656319978.

It can be divided in two parts, 2071 and 9, that added together give a triangular number (2080 = T64).

The spelling of 20719 in words is "twenty thousand, seven hundred nineteen".