125400509 has 8 divisors (see below), whose sum is σ = 138341112. Its totient is φ = 112930560.

The previous prime is 125400503. The next prime is 125400521. The reversal of 125400509 is 905004521.

It can be written as a sum of positive squares in 4 ways, for example, as 1968409 + 123432100 = 1403^2 + 11110^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 125400509 - 2¹² = 125396413 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125400503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 117104 + ... + 118169.

It is an arithmetic number, because the mean of its divisors is an integer number (17292639).

Almost surely, 2^125400509 is an apocalyptic number.

It is an amenable number.

125400509 is a deficient number, since it is larger than the sum of its proper divisors (12940603).

125400509 is a wasteful number, since it uses less digits than its factorization.

125400509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 235327.

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 125400509 is about 11198.2368701506. The cubic root of 125400509 is about 500.5334426754.

The spelling of 125400509 in words is "one hundred twenty-five million, four hundred thousand, five hundred nine".