1287164865 has 32 divisors (see below), whose sum is σ = 2411087616. Its totient is φ = 574064640.

The previous prime is 1287164833. The next prime is 1287164867. The reversal of 1287164865 is 5684617821.

It is not a de Polignac number, because 1287164865 - 2⁵ = 1287164833 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1287164867) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 145192 + ... + 153801.

It is an arithmetic number, because the mean of its divisors is an integer number (75346488).

Almost surely, 2^1287164865 is an apocalyptic number.

1287164865 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1287164865 is a deficient number, since it is larger than the sum of its proper divisors (1123922751).

1287164865 is a wasteful number, since it uses less digits than its factorization.

1287164865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299049.

The product of its digits is 645120, while the sum is 48.

The square root of 1287164865 is about 35877.0799397052. The cubic root of 1287164865 is about 1087.7891570895.

The spelling of 1287164865 in words is "one billion, two hundred eighty-seven million, one hundred sixty-four thousand, eight hundred sixty-five".