20531717 has 2 divisors, whose sum is σ = 20531718. Its totient is φ = 20531716.

The previous prime is 20531713. The next prime is 20531741. The reversal of 20531717 is 71713502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11082241 + 9449476 = 3329^2 + 3074^2 .

It is a cyclic number.

It is not a de Polignac number, because 20531717 - 2² = 20531713 is a 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 (20531713) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10265858 + 10265859.

It is an arithmetic number, because the mean of its divisors is an integer number (10265859).

Almost surely, 2^20531717 is an apocalyptic number.

It is an amenable number.

20531717 is a deficient number, since it is larger than the sum of its proper divisors (1).

20531717 is an equidigital number, since it uses as much as digits as its factorization.

20531717 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1470, while the sum is 26.

The square root of 20531717 is about 4531.1937720649. The cubic root of 20531717 is about 273.8262569122.

The spelling of 20531717 in words is "twenty million, five hundred thirty-one thousand, seven hundred seventeen".