20507471 has 2 divisors, whose sum is σ = 20507472. Its totient is φ = 20507470.

The previous prime is 20507429. The next prime is 20507483. The reversal of 20507471 is 17470502.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20507471 is a prime.

It is a super-3 number, since 3×20507471³ (a number of 23 digits) contains 333 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20507471.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20507401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10253735 + 10253736.

It is an arithmetic number, because the mean of its divisors is an integer number (10253736).

Almost surely, 2^20507471 is an apocalyptic number.

20507471 is a deficient number, since it is larger than the sum of its proper divisors (1).

20507471 is an equidigital number, since it uses as much as digits as its factorization.

20507471 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1960, while the sum is 26.

The square root of 20507471 is about 4528.5175278451. The cubic root of 20507471 is about 273.7184268890.

Adding to 20507471 its reverse (17470502), we get a palindrome (37977973).

The spelling of 20507471 in words is "twenty million, five hundred seven thousand, four hundred seventy-one".