521121065 has 4 divisors (see below), whose sum is σ = 625345284. Its totient is φ = 416896848.

The previous prime is 521121059. The next prime is 521121079. The reversal of 521121065 is 560121125.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 188897536 + 332223529 = 13744^2 + 18227^2 .

It is a cyclic number.

It is not a de Polignac number, because 521121065 - 2⁴ = 521121049 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 521121065.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 52112102 + ... + 52112111.

It is an arithmetic number, because the mean of its divisors is an integer number (156336321).

Almost surely, 2^521121065 is an apocalyptic number.

It is an amenable number.

521121065 is a deficient number, since it is larger than the sum of its proper divisors (104224219).

521121065 is a wasteful number, since it uses less digits than its factorization.

521121065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104224218.

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

The square root of 521121065 is about 22828.0762439589. The cubic root of 521121065 is about 804.7226208934.

The spelling of 521121065 in words is "five hundred twenty-one million, one hundred twenty-one thousand, sixty-five".