1265888643 has 8 divisors (see below), whose sum is σ = 1704238848. Its totient is φ = 835732104.

The previous prime is 1265888621. The next prime is 1265888669. The reversal of 1265888643 is 3468885621.

It is a happy number.

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

It is not a de Polignac number, because 1265888643 - 2⁸ = 1265888387 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1265888683) 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, 2048055 + ... + 2048672.

It is an arithmetic number, because the mean of its divisors is an integer number (213029856).

Almost surely, 2^1265888643 is an apocalyptic number.

1265888643 is a deficient number, since it is larger than the sum of its proper divisors (438350205).

1265888643 is a wasteful number, since it uses less digits than its factorization.

1265888643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4096833.

The product of its digits is 2211840, while the sum is 51.

The square root of 1265888643 is about 35579.3288722539. The cubic root of 1265888643 is about 1081.7622814548.

The spelling of 1265888643 in words is "one billion, two hundred sixty-five million, eight hundred eighty-eight thousand, six hundred forty-three".