20407 has 2 divisors, whose sum is σ = 20408. Its totient is φ = 20406.
The previous prime is 20399. The next prime is 20411. The reversal of 20407 is 70402.
It is a strong prime.
It is a cyclic number.
It is not a de Polignac number, because 20407 - 23 = 20399 is a prime.
It is a Chen prime.
It is a nialpdrome in base 12.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (20477) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (11) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10203 + 10204.
It is an arithmetic number, because the mean of its divisors is an integer number (10204).
220407 is an apocalyptic number.
20407 is a deficient number, since it is larger than the sum of its proper divisors (1).
20407 is an equidigital number, since it uses as much as digits as its factorization.
20407 is an odious number, because the sum of its binary digits is odd.
The product of its (nonzero) digits is 56, while the sum is 13.
The square root of 20407 is about 142.8530713706. The cubic root of 20407 is about 27.3270690913.
Adding to 20407 its reverse (70402), we get a palindrome (90809).
The spelling of 20407 in words is "twenty thousand, four hundred seven", and thus it is an iban number.
• e-mail: info -at- numbersaplenty.com • Privacy notice • done in 0.066 sec. • engine limits •