1287125140 has 72 divisors (see below), whose sum is σ = 3203717832. Its totient is φ = 432956160.

The previous prime is 1287125129. The next prime is 1287125153. The reversal of 1287125140 is 415217821.

It can be written as a sum of positive squares in 4 ways, for example, as 166616464 + 1120508676 = 12908^2 + 33474^2 .

It is a super-2 number, since 2×1287125140² = 3313382252040039200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 39550 + ... + 64330.

It is an arithmetic number, because the mean of its divisors is an integer number (44496081).

Almost surely, 2^1287125140 is an apocalyptic number.

1287125140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1287125140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1601858916).

1287125140 is an abundant number, since it is smaller than the sum of its proper divisors (1916592692).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1287125140 is a wasteful number, since it uses less digits than its factorization.

1287125140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24857 (or 24848 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 31.

The square root of 1287125140 is about 35876.5263089949. The cubic root of 1287125140 is about 1087.7779663788. Note that the first 3 decimals are identical.

The spelling of 1287125140 in words is "one billion, two hundred eighty-seven million, one hundred twenty-five thousand, one hundred forty".