25031205209 has 2 divisors, whose sum is σ = 25031205210. Its totient is φ = 25031205208.

The previous prime is 25031205191. The next prime is 25031205239. The reversal of 25031205209 is 90250213052.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24917569609 + 113635600 = 157853^2 + 10660^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25031205209 is a prime.

It is a super-2 number, since 2×25031205209² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (25031205239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12515602604 + 12515602605.

It is an arithmetic number, because the mean of its divisors is an integer number (12515602605).

Almost surely, 2^25031205209 is an apocalyptic number.

It is an amenable number.

25031205209 is a deficient number, since it is larger than the sum of its proper divisors (1).

25031205209 is an equidigital number, since it uses as much as digits as its factorization.

25031205209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5400, while the sum is 29.

The spelling of 25031205209 in words is "twenty-five billion, thirty-one million, two hundred five thousand, two hundred nine".