125720405 has 4 divisors (see below), whose sum is σ = 150864492. Its totient is φ = 100576320.

The previous prime is 125720383. The next prime is 125720411. The reversal of 125720405 is 504027521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 504027521 = 137 ⋅3679033.

It can be written as a sum of positive squares in 2 ways, for example, as 65642404 + 60078001 = 8102^2 + 7751^2 .

It is not a de Polignac number, because 125720405 - 2⁸ = 125720149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12572036 + ... + 12572045.

It is an arithmetic number, because the mean of its divisors is an integer number (37716123).

Almost surely, 2^125720405 is an apocalyptic number.

It is an amenable number.

125720405 is a deficient number, since it is larger than the sum of its proper divisors (25144087).

125720405 is an equidigital number, since it uses as much as digits as its factorization.

125720405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25144086.

The product of its (nonzero) digits is 2800, while the sum is 26.

The square root of 125720405 is about 11212.5110925252. The cubic root of 125720405 is about 500.9587006114.

Adding to 125720405 its reverse (504027521), we get a palindrome (629747926).

The spelling of 125720405 in words is "one hundred twenty-five million, seven hundred twenty thousand, four hundred five".