20625617 has 2 divisors, whose sum is σ = 20625618. Its totient is φ = 20625616.

The previous prime is 20625599. The next prime is 20625629. The reversal of 20625617 is 71652602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20394256 + 231361 = 4516^2 + 481^2 .

It is a cyclic number.

It is not a de Polignac number, because 20625617 - 2⁸ = 20625361 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20625617.

It is not a weakly prime, because it can be changed into another prime (20625667) 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, 10312808 + 10312809.

It is an arithmetic number, because the mean of its divisors is an integer number (10312809).

Almost surely, 2^20625617 is an apocalyptic number.

It is an amenable number.

20625617 is a deficient number, since it is larger than the sum of its proper divisors (1).

20625617 is an equidigital number, since it uses as much as digits as its factorization.

20625617 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 20625617 is about 4541.5434601025. The cubic root of 20625617 is about 274.2430622413.

The spelling of 20625617 in words is "twenty million, six hundred twenty-five thousand, six hundred seventeen".