521120165 has 8 divisors (see below), whose sum is σ = 627022968. Its totient is φ = 415776960.

The previous prime is 521120147. The next prime is 521120167. The reversal of 521120165 is 561021125.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 106956964 + 414163201 = 10342^2 + 20351^2 .

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

It is not a de Polignac number, because 521120165 - 2⁶ = 521120101 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 521120165.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521120167) 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 in 7 ways as a sum of consecutive naturals, for example, 137846 + ... + 141575.

It is an arithmetic number, because the mean of its divisors is an integer number (78377871).

Almost surely, 2^521120165 is an apocalyptic number.

It is an amenable number.

521120165 is a deficient number, since it is larger than the sum of its proper divisors (105902803).

521120165 is a wasteful number, since it uses less digits than its factorization.

521120165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 279799.

The product of its (nonzero) digits is 600, while the sum is 23.

The square root of 521120165 is about 22828.0565313826. The cubic root of 521120165 is about 804.7221576288.

The spelling of 521120165 in words is "five hundred twenty-one million, one hundred twenty thousand, one hundred sixty-five".