265581216 has 144 divisors (see below), whose sum is σ = 788755968. Its totient is φ = 84672000.

The previous prime is 265581209. The next prime is 265581223. The reversal of 265581216 is 612185562.

265581216 is a `hidden beast` number, since 2 + 65 + 581 + 2 + 16 = 666.

265581216 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (265581209) and next prime (265581223).

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (36).

Its product of digits (28800) is a multiple of the sum of its prime divisors (384).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1348030 + ... + 1348226.

It is an arithmetic number, because the mean of its divisors is an integer number (5477472).

Almost surely, 2^265581216 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 265581216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (394377984).

265581216 is an abundant number, since it is smaller than the sum of its proper divisors (523174752).

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

265581216 is a wasteful number, since it uses less digits than its factorization.

265581216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 395 (or 384 counting only the distinct ones).

The product of its digits is 28800, while the sum is 36.

The square root of 265581216 is about 16296.6627258467. The cubic root of 265581216 is about 642.7850761965.

The spelling of 265581216 in words is "two hundred sixty-five million, five hundred eighty-one thousand, two hundred sixteen".