521617361 has 4 divisors (see below), whose sum is σ = 531459252. Its totient is φ = 511775472.

The previous prime is 521617357. The next prime is 521617363. The reversal of 521617361 is 163716125.

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 468982336 + 52635025 = 21656^2 + 7255^2 .

It is a cyclic number.

It is not a de Polignac number, because 521617361 - 2² = 521617357 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (521617363) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4920866 + ... + 4920971.

It is an arithmetic number, because the mean of its divisors is an integer number (132864813).

Almost surely, 2^521617361 is an apocalyptic number.

It is an amenable number.

521617361 is a deficient number, since it is larger than the sum of its proper divisors (9841891).

521617361 is an equidigital number, since it uses as much as digits as its factorization.

521617361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9841890.

The product of its digits is 7560, while the sum is 32.

The square root of 521617361 is about 22838.9439554459. The cubic root of 521617361 is about 804.9780023052.

The spelling of 521617361 in words is "five hundred twenty-one million, six hundred seventeen thousand, three hundred sixty-one".