521240407 has 2 divisors, whose sum is σ = 521240408. Its totient is φ = 521240406.

The previous prime is 521240389. The next prime is 521240413. The reversal of 521240407 is 704042125.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 521240407 - 2²³ = 512851799 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (521240807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260620203 + 260620204.

It is an arithmetic number, because the mean of its divisors is an integer number (260620204).

Almost surely, 2^521240407 is an apocalyptic number.

521240407 is a deficient number, since it is larger than the sum of its proper divisors (1).

521240407 is an equidigital number, since it uses as much as digits as its factorization.

521240407 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2240, while the sum is 25.

The square root of 521240407 is about 22830.6900246138. The cubic root of 521240407 is about 804.7840460805.

The spelling of 521240407 in words is "five hundred twenty-one million, two hundred forty thousand, four hundred seven".