125412509 has 2 divisors, whose sum is σ = 125412510. Its totient is φ = 125412508.

The previous prime is 125412479. The next prime is 125412541. The reversal of 125412509 is 905214521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 113316025 + 12096484 = 10645^2 + 3478^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-125412509 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (125412569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62706254 + 62706255.

It is an arithmetic number, because the mean of its divisors is an integer number (62706255).

Almost surely, 2^125412509 is an apocalyptic number.

It is an amenable number.

125412509 is a deficient number, since it is larger than the sum of its proper divisors (1).

125412509 is an equidigital number, since it uses as much as digits as its factorization.

125412509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3600, while the sum is 29.

The square root of 125412509 is about 11198.7726559655. The cubic root of 125412509 is about 500.5494080804.

The spelling of 125412509 in words is "one hundred twenty-five million, four hundred twelve thousand, five hundred nine".