1287128713 has 8 divisors (see below), whose sum is σ = 1386579656. Its totient is φ = 1187740800.

The previous prime is 1287128707. The next prime is 1287128747. The reversal of 1287128713 is 3178217821.

It can be written as a sum of positive squares in 4 ways, for example, as 328329 + 1286800384 = 573^2 + 35872^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1287128713 - 2⁹ = 1287128201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1287128113) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32053 + ... + 60013.

It is an arithmetic number, because the mean of its divisors is an integer number (173322457).

Almost surely, 2^1287128713 is an apocalyptic number.

1287128713 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1287128713 is a deficient number, since it is larger than the sum of its proper divisors (99450943).

1287128713 is a wasteful number, since it uses less digits than its factorization.

1287128713 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31515.

The product of its digits is 37632, while the sum is 40.

The square root of 1287128713 is about 35876.5761047511. The cubic root of 1287128713 is about 1087.7789729183.

The spelling of 1287128713 in words is "one billion, two hundred eighty-seven million, one hundred twenty-eight thousand, seven hundred thirteen".