1281950387845 has 8 divisors (see below), whose sum is σ = 1538360956440. Its totient is φ = 1025546649600.

The previous prime is 1281950387803. The next prime is 1281950387867. The reversal of 1281950387845 is 5487830591821.

It can be written as a sum of positive squares in 4 ways, for example, as 870651349569 + 411299038276 = 933087^2 + 641326^2 .

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

It is not a de Polignac number, because 1281950387845 - 2¹⁷ = 1281950256773 is a prime.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 1285180 + ... + 2053189.

It is an arithmetic number, because the mean of its divisors is an integer number (192295119555).

Almost surely, 2^{1281950387845} is an apocalyptic number.

It is an amenable number.

1281950387845 is a deficient number, since it is larger than the sum of its proper divisors (256410568595).

1281950387845 is an equidigital number, since it uses as much as digits as its factorization.

1281950387845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3415175.

The product of its (nonzero) digits is 19353600, while the sum is 61.

The spelling of 1281950387845 in words is "one trillion, two hundred eighty-one billion, nine hundred fifty million, three hundred eighty-seven thousand, eight hundred forty-five".