12515433451621 has 2 divisors, whose sum is σ = 12515433451622. Its totient is φ = 12515433451620.

The previous prime is 12515433451607. The next prime is 12515433451627. The reversal of 12515433451621 is 12615433451521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12269502756225 + 245930695396 = 3502785^2 + 495914^2 .

It is a cyclic number.

It is not a de Polignac number, because 12515433451621 - 2²¹ = 12515431354469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12515433451627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6257716725810 + 6257716725811.

It is an arithmetic number, because the mean of its divisors is an integer number (6257716725811).

Almost surely, 2^{12515433451621} is an apocalyptic number.

It is an amenable number.

12515433451621 is a deficient number, since it is larger than the sum of its proper divisors (1).

12515433451621 is an equidigital number, since it uses as much as digits as its factorization.

12515433451621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432000, while the sum is 43.

The spelling of 12515433451621 in words is "twelve trillion, five hundred fifteen billion, four hundred thirty-three million, four hundred fifty-one thousand, six hundred twenty-one".