20525009 has 2 divisors, whose sum is σ = 20525010. Its totient is φ = 20525008.

The previous prime is 20524991. The next prime is 20525017. The reversal of 20525009 is 90052502.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18190225 + 2334784 = 4265^2 + 1528^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20525009 is a prime.

It is not a weakly prime, because it can be changed into another prime (20525809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10262504 + 10262505.

It is an arithmetic number, because the mean of its divisors is an integer number (10262505).

Almost surely, 2^20525009 is an apocalyptic number.

It is an amenable number.

20525009 is a deficient number, since it is larger than the sum of its proper divisors (1).

20525009 is an equidigital number, since it uses as much as digits as its factorization.

20525009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 900, while the sum is 23.

The square root of 20525009 is about 4530.4535093079. The cubic root of 20525009 is about 273.7964327040.

The spelling of 20525009 in words is "twenty million, five hundred twenty-five thousand, nine".