521540003 has 2 divisors, whose sum is σ = 521540004. Its totient is φ = 521540002.

The previous prime is 521539961. The next prime is 521540023. The reversal of 521540003 is 300045125.

It is an a-pointer prime, because the next prime (521540023) can be obtained adding 521540003 to its sum of digits (20).

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 521540003 - 2⁸ = 521539747 is a prime.

It is not a weakly prime, because it can be changed into another prime (521540023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260770001 + 260770002.

It is an arithmetic number, because the mean of its divisors is an integer number (260770002).

Almost surely, 2^521540003 is an apocalyptic number.

521540003 is a deficient number, since it is larger than the sum of its proper divisors (1).

521540003 is an equidigital number, since it uses as much as digits as its factorization.

521540003 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 600, while the sum is 20.

The square root of 521540003 is about 22837.2503379895. The cubic root of 521540003 is about 804.9382064883.

Adding to 521540003 its reverse (300045125), we get a palindrome (821585128).

The spelling of 521540003 in words is "five hundred twenty-one million, five hundred forty thousand, three".