125291009 has 2 divisors, whose sum is σ = 125291010. Its totient is φ = 125291008.

The previous prime is 125290999. The next prime is 125291017. The reversal of 125291009 is 900192521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 120384784 + 4906225 = 10972^2 + 2215^2 .

It is an emirp because it is prime and its reverse (900192521) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 125291009 - 2¹⁶ = 125225473 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (125291029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62645504 + 62645505.

It is an arithmetic number, because the mean of its divisors is an integer number (62645505).

Almost surely, 2^125291009 is an apocalyptic number.

It is an amenable number.

125291009 is a deficient number, since it is larger than the sum of its proper divisors (1).

125291009 is an equidigital number, since it uses as much as digits as its factorization.

125291009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1620, while the sum is 29.

The square root of 125291009 is about 11193.3466398571. The cubic root of 125291009 is about 500.3877112822.

The spelling of 125291009 in words is "one hundred twenty-five million, two hundred ninety-one thousand, nine".