125507209 has 9 divisors (see below), whose sum is σ = 133526887. Its totient is φ = 117945184.

The previous prime is 125507203. The next prime is 125507227. The reversal of 125507209 is 902705521.

The square root of 125507209 is 11203.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 97713225 + 27793984 = 9885^2 + 5272^2 .

It is not a de Polignac number, because 125507209 - 2⁹ = 125506697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (125507203) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 190122 + ... + 190780.

Almost surely, 2^125507209 is an apocalyptic number.

125507209 is the 11203-rd square number.

125507209 is the 5602-nd centered octagonal number.

It is an amenable number.

125507209 is a deficient number, since it is larger than the sum of its proper divisors (8019678).

125507209 is an frugal number, since it uses more digits than its factorization.

125507209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1352 (or 676 counting only the distinct ones).

The product of its (nonzero) digits is 6300, while the sum is 31.

The cubic root of 125507209 is about 500.6753660174.

The spelling of 125507209 in words is "one hundred twenty-five million, five hundred seven thousand, two hundred nine".