127840561643 has 4 divisors (see below), whose sum is σ = 127850539440. Its totient is φ = 127830583848.

The previous prime is 127840561627. The next prime is 127840561711. The reversal of 127840561643 is 346165048721.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 346165048721 = 31091 ⋅11133931.

It is a cyclic number.

It is not a de Polignac number, because 127840561643 - 2⁴ = 127840561627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (127840561243) 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, 4969655 + ... + 4995312.

It is an arithmetic number, because the mean of its divisors is an integer number (31962634860).

Almost surely, 2^127840561643 is an apocalyptic number.

127840561643 is a deficient number, since it is larger than the sum of its proper divisors (9977797).

127840561643 is an equidigital number, since it uses as much as digits as its factorization.

127840561643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9977796.

The product of its (nonzero) digits is 967680, while the sum is 47.

The spelling of 127840561643 in words is "one hundred twenty-seven billion, eight hundred forty million, five hundred sixty-one thousand, six hundred forty-three".