125238819550561 has 4 divisors (see below), whose sum is σ = 125238982202800. Its totient is φ = 125238656898324.

The previous prime is 125238819550553. The next prime is 125238819550571. The reversal of 125238819550561 is 165055918832521.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 125238819550561 - 2³ = 125238819550553 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 125238819550561.

It is not an unprimeable number, because it can be changed into a prime (125238819550501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 80165631 + ... + 81712948.

It is an arithmetic number, because the mean of its divisors is an integer number (31309745550700).

Almost surely, 2^{125238819550561} is an apocalyptic number.

It is an amenable number.

125238819550561 is a deficient number, since it is larger than the sum of its proper divisors (162652239).

125238819550561 is an equidigital number, since it uses as much as digits as its factorization.

125238819550561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162652238.

The product of its (nonzero) digits is 25920000, while the sum is 61.

The spelling of 125238819550561 in words is "one hundred twenty-five trillion, two hundred thirty-eight billion, eight hundred nineteen million, five hundred fifty thousand, five hundred sixty-one".