12521403 has 6 divisors (see below), whose sum is σ = 18086484. Its totient is φ = 8347596.

The previous prime is 12521381. The next prime is 12521447. The reversal of 12521403 is 30412521.

It is not a de Polignac number, because 12521403 - 2⁵ = 12521371 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12521473) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 695625 + ... + 695642.

It is an arithmetic number, because the mean of its divisors is an integer number (3014414).

Almost surely, 2^12521403 is an apocalyptic number.

12521403 is a deficient number, since it is larger than the sum of its proper divisors (5565081).

12521403 is a wasteful number, since it uses less digits than its factorization.

12521403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1391273 (or 1391270 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 12521403 is about 3538.5594526587. The cubic root of 12521403 is about 232.2118247199.

Adding to 12521403 its reverse (30412521), we get a palindrome (42933924).

It can be divided in two parts, 125 and 21403, that added together give a triangular number (21528 = T₂₀₇).

The spelling of 12521403 in words is "twelve million, five hundred twenty-one thousand, four hundred three".