521662987 has 2 divisors, whose sum is σ = 521662988. Its totient is φ = 521662986.

The previous prime is 521662979. The next prime is 521663029. The reversal of 521662987 is 789266125.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 521662987 - 2³ = 521662979 is a prime.

It is not a weakly prime, because it can be changed into another prime (521662937) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260831493 + 260831494.

It is an arithmetic number, because the mean of its divisors is an integer number (260831494).

Almost surely, 2^521662987 is an apocalyptic number.

521662987 is a deficient number, since it is larger than the sum of its proper divisors (1).

521662987 is an equidigital number, since it uses as much as digits as its factorization.

521662987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 362880, while the sum is 46.

The square root of 521662987 is about 22839.9427976517. The cubic root of 521662987 is about 805.0014721627.

The spelling of 521662987 in words is "five hundred twenty-one million, six hundred sixty-two thousand, nine hundred eighty-seven".