20507 has 2 divisors, whose sum is σ = 20508. Its totient is φ = 20506.

The previous prime is 20483. The next prime is 20509. The reversal of 20507 is 70502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20507 - 2⁶ = 20443 is a prime.

Together with 20509, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 20491 and 20500.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 20507.

It is not a weakly prime, because it can be changed into another prime (20509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10253 + 10254.

It is an arithmetic number, because the mean of its divisors is an integer number (10254).

2²⁰⁵⁰⁷ is an apocalyptic number.

20507 is a deficient number, since it is larger than the sum of its proper divisors (1).

20507 is an equidigital number, since it uses as much as digits as its factorization.

20507 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 70, while the sum is 14.

The square root of 20507 is about 143.2026536067. The cubic root of 20507 is about 27.3716331354.

The spelling of 20507 in words is "twenty thousand, five hundred seven".