521105987 has 2 divisors, whose sum is σ = 521105988. Its totient is φ = 521105986.

The previous prime is 521105957. The next prime is 521106073. The reversal of 521105987 is 789501125.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 521105987 - 2¹² = 521101891 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 521105987.

It is not a weakly prime, because it can be changed into another prime (521105957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260552993 + 260552994.

It is an arithmetic number, because the mean of its divisors is an integer number (260552994).

Almost surely, 2^521105987 is an apocalyptic number.

521105987 is a deficient number, since it is larger than the sum of its proper divisors (1).

521105987 is an equidigital number, since it uses as much as digits as its factorization.

521105987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25200, while the sum is 38.

The square root of 521105987 is about 22827.7459903513. The cubic root of 521105987 is about 804.7148595972.

The spelling of 521105987 in words is "five hundred twenty-one million, one hundred five thousand, nine hundred eighty-seven".