521651161 has 4 divisors (see below), whose sum is σ = 527512500. Its totient is φ = 515789824.

The previous prime is 521651153. The next prime is 521651173. The reversal of 521651161 is 161156125.

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 322417936 + 199233225 = 17956^2 + 14115^2 .

It is a cyclic number.

It is not a de Polignac number, because 521651161 - 2³ = 521651153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (521651191) 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, 2930536 + ... + 2930713.

It is an arithmetic number, because the mean of its divisors is an integer number (131878125).

Almost surely, 2^521651161 is an apocalyptic number.

It is an amenable number.

521651161 is a deficient number, since it is larger than the sum of its proper divisors (5861339).

521651161 is an equidigital number, since it uses as much as digits as its factorization.

521651161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5861338.

The product of its digits is 1800, while the sum is 28.

The square root of 521651161 is about 22839.6839076201. The cubic root of 521651161 is about 804.9953890404.

The spelling of 521651161 in words is "five hundred twenty-one million, six hundred fifty-one thousand, one hundred sixty-one".