1251387513871 has 16 divisors (see below), whose sum is σ = 1424609653248. Its totient is φ = 1088082626400.

The previous prime is 1251387513869. The next prime is 1251387513911. The reversal of 1251387513871 is 1783157831521.

It is a happy number.

It is not a de Polignac number, because 1251387513871 - 2¹ = 1251387513869 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1251387513811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3384205 + ... + 3735721.

It is an arithmetic number, because the mean of its divisors is an integer number (89038103328).

Almost surely, 2^{1251387513871} is an apocalyptic number.

1251387513871 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1251387513871 is a deficient number, since it is larger than the sum of its proper divisors (173222139377).

1251387513871 is a wasteful number, since it uses less digits than its factorization.

1251387513871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 365622.

The product of its digits is 1411200, while the sum is 52.

The spelling of 1251387513871 in words is "one trillion, two hundred fifty-one billion, three hundred eighty-seven million, five hundred thirteen thousand, eight hundred seventy-one".