1264138888765 has 8 divisors (see below), whose sum is σ = 1516979779128. Its totient is φ = 1011302369280.

The previous prime is 1264138888759. The next prime is 1264138888847. The reversal of 1264138888765 is 5678888314621.

It can be written as a sum of positive squares in 4 ways, for example, as 226859784804 + 1037279103961 = 476298^2 + 1018469^2 .

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

It is a de Polignac number, because none of the positive numbers 2^k-1264138888765 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1264138888765.

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, 418632 + ... + 1644241.

It is an arithmetic number, because the mean of its divisors is an integer number (189622472391).

Almost surely, 2^{1264138888765} is an apocalyptic number.

It is an amenable number.

1264138888765 is a deficient number, since it is larger than the sum of its proper divisors (252840890363).

1264138888765 is a wasteful number, since it uses less digits than its factorization.

1264138888765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2185439.

The product of its digits is 123863040, while the sum is 67.

The spelling of 1264138888765 in words is "one trillion, two hundred sixty-four billion, one hundred thirty-eight million, eight hundred eighty-eight thousand, seven hundred sixty-five".