20731247 has 2 divisors, whose sum is σ = 20731248. Its totient is φ = 20731246.

The previous prime is 20731241. The next prime is 20731253. The reversal of 20731247 is 74213702.

It is a balanced prime because it is at equal distance from previous prime (20731241) and next prime (20731253).

It is a cyclic number.

It is not a de Polignac number, because 20731247 - 2⁴ = 20731231 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20731241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10365623 + 10365624.

It is an arithmetic number, because the mean of its divisors is an integer number (10365624).

Almost surely, 2^20731247 is an apocalyptic number.

20731247 is a deficient number, since it is larger than the sum of its proper divisors (1).

20731247 is an equidigital number, since it uses as much as digits as its factorization.

20731247 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2352, while the sum is 26.

The square root of 20731247 is about 4553.1579151178. The cubic root of 20731247 is about 274.7104257647.

Adding to 20731247 its reverse (74213702), we get a palindrome (94944949).

The spelling of 20731247 in words is "twenty million, seven hundred thirty-one thousand, two hundred forty-seven".