1265037271890 has 128 divisors (see below), whose sum is σ = 3693160562688. Its totient is φ = 270717496320.

The previous prime is 1265037271867. The next prime is 1265037271903. The reversal of 1265037271890 is 981727305621.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a Curzon 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 63 ways as a sum of consecutive naturals, for example, 245754 + ... + 1609493.

It is an arithmetic number, because the mean of its divisors is an integer number (28852816896).

Almost surely, 2^{1265037271890} is an apocalyptic number.

1265037271890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1265037271890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1846580281344).

1265037271890 is an abundant number, since it is smaller than the sum of its proper divisors (2428123290798).

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

1265037271890 is a wasteful number, since it uses less digits than its factorization.

1265037271890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1855472.

The product of its (nonzero) digits is 1270080, while the sum is 51.

The spelling of 1265037271890 in words is "one trillion, two hundred sixty-five billion, thirty-seven million, two hundred seventy-one thousand, eight hundred ninety".