521330987 has 4 divisors (see below), whose sum is σ = 548769480. Its totient is φ = 493892496.

The previous prime is 521330983. The next prime is 521331001. The reversal of 521330987 is 789033125.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 521330987 - 2² = 521330983 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 521330987.

It is not an unprimeable number, because it can be changed into a prime (521330981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13719218 + ... + 13719255.

It is an arithmetic number, because the mean of its divisors is an integer number (137192370).

Almost surely, 2^521330987 is an apocalyptic number.

521330987 is a deficient number, since it is larger than the sum of its proper divisors (27438493).

521330987 is a wasteful number, since it uses less digits than its factorization.

521330987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27438492.

The product of its (nonzero) digits is 45360, while the sum is 38.

The square root of 521330987 is about 22832.6736717363. The cubic root of 521330987 is about 804.8306612416.

The spelling of 521330987 in words is "five hundred twenty-one million, three hundred thirty thousand, nine hundred eighty-seven".