265561920 has 336 divisors, whose sum is σ = 1013502672. Its totient is φ = 63406080.

The previous prime is 265561873. The next prime is 265561921. The reversal of 265561920 is 29165562.

265561920 is a `hidden beast` number, since 2 + 6 + 5 + 561 + 92 + 0 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 24443136 + 241118784 = 4944^2 + 15528^2 .

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (265561921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1534954 + ... + 1535126.

It is an arithmetic number, because the mean of its divisors is an integer number (3016377).

Almost surely, 2^265561920 is an apocalyptic number.

265561920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 265561920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (506751336).

265561920 is an abundant number, since it is smaller than the sum of its proper divisors (747940752).

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

265561920 is a wasteful number, since it uses less digits than its factorization.

265561920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 250 (or 237 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The square root of 265561920 is about 16296.0706920411. The cubic root of 265561920 is about 642.7695084775.

The spelling of 265561920 in words is "two hundred sixty-five million, five hundred sixty-one thousand, nine hundred twenty".