102521 has 4 divisors (see below), whose sum is σ = 103332. Its totient is φ = 101712.

The previous prime is 102503. The next prime is 102523. The reversal of 102521 is 125201.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 26896 + 75625 = 164^2 + 275^2 .

It is a cyclic number.

It is not a de Polignac number, because 102521 - 2¹⁴ = 86137 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (102523) 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, 170 + ... + 483.

It is an arithmetic number, because the mean of its divisors is an integer number (25833).

2¹⁰²⁵²¹ is an apocalyptic number.

It is an amenable number.

102521 is a deficient number, since it is larger than the sum of its proper divisors (811).

102521 is an equidigital number, since it uses as much as digits as its factorization.

102521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 810.

The product of its (nonzero) digits is 20, while the sum is 11.

The square root of 102521 is about 320.1890066820. The cubic root of 102521 is about 46.8027039614.

Adding to 102521 its reverse (125201), we get a palindrome (227722).

The spelling of 102521 in words is "one hundred two thousand, five hundred twenty-one".