3125121305 has 24 divisors (see below), whose sum is σ = 4002376536. Its totient is φ = 2334356480.

The previous prime is 3125121301. The next prime is 3125121319. The reversal of 3125121305 is 5031215213.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 205664281 + 2919457024 = 14341^2 + 54032^2 .

It is not a de Polignac number, because 3125121305 - 2² = 3125121301 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3125121301) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6778775 + ... + 6779235.

It is an arithmetic number, because the mean of its divisors is an integer number (166765689).

Almost surely, 2^3125121305 is an apocalyptic number.

It is an amenable number.

3125121305 is a deficient number, since it is larger than the sum of its proper divisors (877255231).

3125121305 is an equidigital number, since it uses as much as digits as its factorization.

3125121305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1117 (or 656 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 23.

The square root of 3125121305 is about 55902.7844118699. The cubic root of 3125121305 is about 1462.0277860868.

Adding to 3125121305 its reverse (5031215213), we get a palindrome (8156336518).

The spelling of 3125121305 in words is "three billion, one hundred twenty-five million, one hundred twenty-one thousand, three hundred five".