521665117 has 8 divisors (see below), whose sum is σ = 538755840. Its totient is φ = 504590880.

The previous prime is 521665091. The next prime is 521665141. The reversal of 521665117 is 711566125.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-521665117 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521665817) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 119658 + ... + 123940.

It is an arithmetic number, because the mean of its divisors is an integer number (67344480).

Almost surely, 2^521665117 is an apocalyptic number.

It is an amenable number.

521665117 is a deficient number, since it is larger than the sum of its proper divisors (17090723).

521665117 is a wasteful number, since it uses less digits than its factorization.

521665117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8243.

The product of its digits is 12600, while the sum is 34.

The square root of 521665117 is about 22839.9894264424. The cubic root of 521665117 is about 805.0025677940.

The spelling of 521665117 in words is "five hundred twenty-one million, six hundred sixty-five thousand, one hundred seventeen".