12541540421 has 2 divisors, whose sum is σ = 12541540422. Its totient is φ = 12541540420.

The previous prime is 12541540399. The next prime is 12541540469. The reversal of 12541540421 is 12404514521.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8410907521 + 4130632900 = 91711^2 + 64270^2 .

It is a cyclic number.

It is not a de Polignac number, because 12541540421 - 2⁶ = 12541540357 is a prime.

It is a super-2 number, since 2×12541540421² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12541540721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6270770210 + 6270770211.

It is an arithmetic number, because the mean of its divisors is an integer number (6270770211).

Almost surely, 2^12541540421 is an apocalyptic number.

It is an amenable number.

12541540421 is a deficient number, since it is larger than the sum of its proper divisors (1).

12541540421 is an equidigital number, since it uses as much as digits as its factorization.

12541540421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6400, while the sum is 29.

The spelling of 12541540421 in words is "twelve billion, five hundred forty-one million, five hundred forty thousand, four hundred twenty-one".