521545009 has 2 divisors, whose sum is σ = 521545010. Its totient is φ = 521545008.

The previous prime is 521544997. The next prime is 521545021. The reversal of 521545009 is 900545125.

It is a balanced prime because it is at equal distance from previous prime (521544997) and next prime (521545021).

It can be written as a sum of positive squares in only one way, i.e., 398401600 + 123143409 = 19960^2 + 11097^2 .

It is a cyclic number.

It is not a de Polignac number, because 521545009 - 2⁵ = 521544977 is a prime.

It is not a weakly prime, because it can be changed into another prime (521545039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260772504 + 260772505.

It is an arithmetic number, because the mean of its divisors is an integer number (260772505).

Almost surely, 2^521545009 is an apocalyptic number.

It is an amenable number.

521545009 is a deficient number, since it is larger than the sum of its proper divisors (1).

521545009 is an equidigital number, since it uses as much as digits as its factorization.

521545009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9000, while the sum is 31.

The square root of 521545009 is about 22837.3599393625. The cubic root of 521545009 is about 804.9407818790.

The spelling of 521545009 in words is "five hundred twenty-one million, five hundred forty-five thousand, nine".