126378617566 has 4 divisors (see below), whose sum is σ = 189567926352. Its totient is φ = 63189308782.

The previous prime is 126378617543. The next prime is 126378617609. The reversal of 126378617566 is 665716873621.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 126378617566.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31594654390 + ... + 31594654393.

It is an arithmetic number, because the mean of its divisors is an integer number (47391981588).

Almost surely, 2^126378617566 is an apocalyptic number.

126378617566 is a deficient number, since it is larger than the sum of its proper divisors (63189308786).

126378617566 is an equidigital number, since it uses as much as digits as its factorization.

126378617566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63189308785.

The product of its digits is 15240960, while the sum is 58.

The spelling of 126378617566 in words is "one hundred twenty-six billion, three hundred seventy-eight million, six hundred seventeen thousand, five hundred sixty-six".