265378777665 has 32 divisors (see below), whose sum is σ = 435526291200. Its totient is φ = 137937841920.

The previous prime is 265378777619. The next prime is 265378777681. The reversal of 265378777665 is 566777873562.

It is not a de Polignac number, because 265378777665 - 2¹³ = 265378769473 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 265378777665.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1230685 + ... + 1430154.

It is an arithmetic number, because the mean of its divisors is an integer number (13610196600).

Almost surely, 2^265378777665 is an apocalyptic number.

It is an amenable number.

265378777665 is a deficient number, since it is larger than the sum of its proper divisors (170147513535).

265378777665 is a wasteful number, since it uses less digits than its factorization.

265378777665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2661017.

The product of its digits is 622339200, while the sum is 69.

The spelling of 265378777665 in words is "two hundred sixty-five billion, three hundred seventy-eight million, seven hundred seventy-seven thousand, six hundred sixty-five".