20501471 has 2 divisors, whose sum is σ = 20501472. Its totient is φ = 20501470.

The previous prime is 20501449. The next prime is 20501491. The reversal of 20501471 is 17410502.

It is an a-pointer prime, because the next prime (20501491) can be obtained adding 20501471 to its sum of digits (20).

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20501471 - 2¹⁸ = 20239327 is a prime.

It is a super-3 number, since 3×20501471³ (a number of 23 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20501491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10250735 + 10250736.

It is an arithmetic number, because the mean of its divisors is an integer number (10250736).

Almost surely, 2^20501471 is an apocalyptic number.

20501471 is a deficient number, since it is larger than the sum of its proper divisors (1).

20501471 is an equidigital number, since it uses as much as digits as its factorization.

20501471 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 280, while the sum is 20.

The square root of 20501471 is about 4527.8550109296. The cubic root of 20501471 is about 273.6917297769.

Adding to 20501471 its reverse (17410502), we get a palindrome (37911973).

The spelling of 20501471 in words is "twenty million, five hundred one thousand, four hundred seventy-one".