12402521 has 4 divisors (see below), whose sum is σ = 12409572. Its totient is φ = 12395472.

The previous prime is 12402499. The next prime is 12402527. The reversal of 12402521 is 12520421.

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 11424400 + 978121 = 3380^2 + 989^2 .

It is a cyclic number.

It is not a de Polignac number, because 12402521 - 2⁶ = 12402457 is a prime.

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 12402521.

It is not an unprimeable number, because it can be changed into a prime (12402527) 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, 1535 + ... + 5211.

It is an arithmetic number, because the mean of its divisors is an integer number (3102393).

Almost surely, 2^12402521 is an apocalyptic number.

It is an amenable number.

12402521 is a deficient number, since it is larger than the sum of its proper divisors (7051).

12402521 is an equidigital number, since it uses as much as digits as its factorization.

12402521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7050.

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 12402521 is about 3521.7213120859. The cubic root of 12402521 is about 231.4745900860.

Adding to 12402521 its reverse (12520421), we get a palindrome (24922942).

The spelling of 12402521 in words is "twelve million, four hundred two thousand, five hundred twenty-one".