1251540525305 has 16 divisors (see below), whose sum is σ = 1752917552640. Its totient is φ = 839939658432.

The previous prime is 1251540525299. The next prime is 1251540525307. The reversal of 1251540525305 is 5035250451521.

It is not a de Polignac number, because 1251540525305 - 2¹⁸ = 1251540263161 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1251540525307) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 380405810 + ... + 380409099.

It is an arithmetic number, because the mean of its divisors is an integer number (109557347040).

Almost surely, 2^{1251540525305} is an apocalyptic number.

It is an amenable number.

1251540525305 is a deficient number, since it is larger than the sum of its proper divisors (501377027335).

1251540525305 is an equidigital number, since it uses as much as digits as its factorization.

1251540525305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 760814968.

The product of its (nonzero) digits is 150000, while the sum is 38.

Adding to 1251540525305 its reverse (5035250451521), we get a palindrome (6286790976826).

The spelling of 1251540525305 in words is "one trillion, two hundred fifty-one billion, five hundred forty million, five hundred twenty-five thousand, three hundred five".