125721163 has 4 divisors (see below), whose sum is σ = 125845560. Its totient is φ = 125596768.

The previous prime is 125721149. The next prime is 125721173. The reversal of 125721163 is 361127521.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 361127521 = 67 ⋅5389963.

It is a cyclic number.

It is not a de Polignac number, because 125721163 - 2²⁵ = 92166731 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (125721143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 60670 + ... + 62707.

It is an arithmetic number, because the mean of its divisors is an integer number (31461390).

Almost surely, 2^125721163 is an apocalyptic number.

125721163 is a deficient number, since it is larger than the sum of its proper divisors (124397).

125721163 is a wasteful number, since it uses less digits than its factorization.

125721163 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124396.

The product of its digits is 2520, while the sum is 28.

The square root of 125721163 is about 11212.5448940015. The cubic root of 125721163 is about 500.9597074115.

Adding to 125721163 its reverse (361127521), we get a palindrome (486848684).

The spelling of 125721163 in words is "one hundred twenty-five million, seven hundred twenty-one thousand, one hundred sixty-three".