12545921 has 4 divisors (see below), whose sum is σ = 12555012. Its totient is φ = 12536832.

The previous prime is 12545903. The next prime is 12545927. The reversal of 12545921 is 12954521.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12954521 = 643 ⋅20147.

It can be written as a sum of positive squares in 2 ways, for example, as 7639696 + 4906225 = 2764^2 + 2215^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12545921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12545927) 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, 2000 + ... + 5393.

It is an arithmetic number, because the mean of its divisors is an integer number (3138753).

Almost surely, 2^12545921 is an apocalyptic number.

It is an amenable number.

12545921 is a deficient number, since it is larger than the sum of its proper divisors (9091).

12545921 is an equidigital number, since it uses as much as digits as its factorization.

12545921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9090.

The product of its digits is 3600, while the sum is 29.

The square root of 12545921 is about 3542.0221625507. The cubic root of 12545921 is about 232.3632895762.

The spelling of 12545921 in words is "twelve million, five hundred forty-five thousand, nine hundred twenty-one".