20730247 has 4 divisors (see below), whose sum is σ = 20755240. Its totient is φ = 20705256.

The previous prime is 20730239. The next prime is 20730253. The reversal of 20730247 is 74203702.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20730247 - 2³ = 20730239 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20730217) 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, 11208 + ... + 12925.

It is an arithmetic number, because the mean of its divisors is an integer number (5188810).

Almost surely, 2^20730247 is an apocalyptic number.

20730247 is a deficient number, since it is larger than the sum of its proper divisors (24993).

20730247 is an equidigital number, since it uses as much as digits as its factorization.

20730247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24992.

The product of its (nonzero) digits is 2352, while the sum is 25.

The square root of 20730247 is about 4553.0480998997. The cubic root of 20730247 is about 274.7060086829.

Adding to 20730247 its reverse (74203702), we get a palindrome (94933949).

The spelling of 20730247 in words is "twenty million, seven hundred thirty thousand, two hundred forty-seven".