12538427861 has 2 divisors, whose sum is σ = 12538427862. Its totient is φ = 12538427860.

The previous prime is 12538427819. The next prime is 12538427879. The reversal of 12538427861 is 16872483521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11362280836 + 1176147025 = 106594^2 + 34295^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12538427861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12538427801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6269213930 + 6269213931.

It is an arithmetic number, because the mean of its divisors is an integer number (6269213931).

Almost surely, 2^12538427861 is an apocalyptic number.

It is an amenable number.

12538427861 is a deficient number, since it is larger than the sum of its proper divisors (1).

12538427861 is an equidigital number, since it uses as much as digits as its factorization.

12538427861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 645120, while the sum is 47.

The spelling of 12538427861 in words is "twelve billion, five hundred thirty-eight million, four hundred twenty-seven thousand, eight hundred sixty-one".