20617523 has 2 divisors, whose sum is σ = 20617524. Its totient is φ = 20617522.

The previous prime is 20617517. The next prime is 20617559. The reversal of 20617523 is 32571602.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20617523 - 2¹² = 20613427 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20617492 and 20617501.

It is not a weakly prime, because it can be changed into another prime (20617423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10308761 + 10308762.

It is an arithmetic number, because the mean of its divisors is an integer number (10308762).

Almost surely, 2^20617523 is an apocalyptic number.

20617523 is a deficient number, since it is larger than the sum of its proper divisors (1).

20617523 is an equidigital number, since it uses as much as digits as its factorization.

20617523 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2520, while the sum is 26.

The square root of 20617523 is about 4540.6522659195. The cubic root of 20617523 is about 274.2071843043.

The spelling of 20617523 in words is "twenty million, six hundred seventeen thousand, five hundred twenty-three".