521553321 has 24 divisors (see below), whose sum is σ = 773874816. Its totient is φ = 338294880.

The previous prime is 521553317. The next prime is 521553323. The reversal of 521553321 is 123355125.

It is a happy number.

It is not a de Polignac number, because 521553321 - 2² = 521553317 is a prime.

It is a super-2 number, since 2×521553321² = 544035733292258082, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (521553323) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 102391 + ... + 107363.

It is an arithmetic number, because the mean of its divisors is an integer number (32244784).

Almost surely, 2^521553321 is an apocalyptic number.

It is an amenable number.

521553321 is a deficient number, since it is larger than the sum of its proper divisors (252321495).

521553321 is a wasteful number, since it uses less digits than its factorization.

521553321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5293 (or 5290 counting only the distinct ones).

The product of its digits is 4500, while the sum is 27.

The square root of 521553321 is about 22837.5419211438. The cubic root of 521553321 is about 804.9450580406.

The spelling of 521553321 in words is "five hundred twenty-one million, five hundred fifty-three thousand, three hundred twenty-one".