10521521 has 4 divisors (see below), whose sum is σ = 11140452. Its totient is φ = 9902592.

The previous prime is 10521503. The next prime is 10521559. The reversal of 10521521 is 12512501.

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 6195121 + 4326400 = 2489^2 + 2080^2 .

It is a cyclic number.

It is not a de Polignac number, because 10521521 - 2¹⁴ = 10505137 is a prime.

It is a super-2 number, since 2×10521521² = 221404808306882, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (17), and also a Moran number because the ratio is a prime number: 618913 = 10521521 / (1 + 0 + 5 + 2 + 1 + 5 + 2 + 1).

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 10521521.

It is not an unprimeable number, because it can be changed into a prime (10521571) 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, 309440 + ... + 309473.

It is an arithmetic number, because the mean of its divisors is an integer number (2785113).

Almost surely, 2^10521521 is an apocalyptic number.

It is an amenable number.

10521521 is a deficient number, since it is larger than the sum of its proper divisors (618931).

10521521 is an equidigital number, since it uses as much as digits as its factorization.

10521521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 618930.

The product of its (nonzero) digits is 100, while the sum is 17.

The square root of 10521521 is about 3243.6894117656. The cubic root of 10521521 is about 219.1254606632.

The spelling of 10521521 in words is "ten million, five hundred twenty-one thousand, five hundred twenty-one".