20518601 has 2 divisors, whose sum is σ = 20518602. Its totient is φ = 20518600.

The previous prime is 20518577. The next prime is 20518637. The reversal of 20518601 is 10681502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12390400 + 8128201 = 3520^2 + 2851^2 .

It is a cyclic number.

It is not a de Polignac number, because 20518601 - 2¹⁰ = 20517577 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (20518301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10259300 + 10259301.

It is an arithmetic number, because the mean of its divisors is an integer number (10259301).

Almost surely, 2^20518601 is an apocalyptic number.

It is an amenable number.

20518601 is a deficient number, since it is larger than the sum of its proper divisors (1).

20518601 is an equidigital number, since it uses as much as digits as its factorization.

20518601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 480, while the sum is 23.

The square root of 20518601 is about 4529.7462401331. The cubic root of 20518601 is about 273.7679362462.

The spelling of 20518601 in words is "twenty million, five hundred eighteen thousand, six hundred one".