12640378987 has 2 divisors, whose sum is σ = 12640378988. Its totient is φ = 12640378986.

The previous prime is 12640378979. The next prime is 12640379047. The reversal of 12640378987 is 78987304621.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 12640378987 - 2³ = 12640378979 is a prime.

It is a super-2 number, since 2×12640378987² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (12640378937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6320189493 + 6320189494.

It is an arithmetic number, because the mean of its divisors is an integer number (6320189494).

Almost surely, 2^12640378987 is an apocalyptic number.

12640378987 is a deficient number, since it is larger than the sum of its proper divisors (1).

12640378987 is an equidigital number, since it uses as much as digits as its factorization.

12640378987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4064256, while the sum is 55.

The spelling of 12640378987 in words is "twelve billion, six hundred forty million, three hundred seventy-eight thousand, nine hundred eighty-seven".