125556123561 has 8 divisors (see below), whose sum is σ = 182627088864. Its totient is φ = 76094620320.

The previous prime is 125556123547. The next prime is 125556123571. The reversal of 125556123561 is 165321655521.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 125556123561 - 2¹⁰ = 125556122537 is a prime.

It is not an unprimeable number, because it can be changed into a prime (125556123571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1902365476 + ... + 1902365541.

It is an arithmetic number, because the mean of its divisors is an integer number (22828386108).

Almost surely, 2^125556123561 is an apocalyptic number.

125556123561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

125556123561 is a deficient number, since it is larger than the sum of its proper divisors (57070965303).

125556123561 is a wasteful number, since it uses less digits than its factorization.

125556123561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3804731031.

The product of its digits is 270000, while the sum is 42.

The spelling of 125556123561 in words is "one hundred twenty-five billion, five hundred fifty-six million, one hundred twenty-three thousand, five hundred sixty-one".