126378617513 has 4 divisors (see below), whose sum is σ = 126396686340. Its totient is φ = 126360548688.

The previous prime is 126378617473. The next prime is 126378617539. The reversal of 126378617513 is 315716873621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 315716873621 = 19 ⋅16616677559.

It can be written as a sum of positive squares in 2 ways, for example, as 34297928809 + 92080688704 = 185197^2 + 303448^2 .

It is a cyclic number.

It is not a de Polignac number, because 126378617513 - 2⁸ = 126378617257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (126378617543) 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, 9023918 + ... + 9037911.

It is an arithmetic number, because the mean of its divisors is an integer number (31599171585).

Almost surely, 2^126378617513 is an apocalyptic number.

It is an amenable number.

126378617513 is a deficient number, since it is larger than the sum of its proper divisors (18068827).

126378617513 is an equidigital number, since it uses as much as digits as its factorization.

126378617513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18068826.

The product of its digits is 1270080, while the sum is 50.

The spelling of 126378617513 in words is "one hundred twenty-six billion, three hundred seventy-eight million, six hundred seventeen thousand, five hundred thirteen".