It is a semiprime because it is the product of two primes.
It is a cyclic number.
It is a Duffinian number.
It is a congruent number.
It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 20351.
220351 is an apocalyptic number.
20351 is an equidigital number, since it uses as much as digits as its factorization.
20351 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 480.
The square root of 20351 is about 142.6569311320. The cubic root of 20351 is about 27.3020496075.
Adding to 20351 its reverse (15302), we get a palindrome (35653).
The spelling of 20351 in words is "twenty thousand, three hundred fifty-one".