265666256541 has 32 divisors (see below), whose sum is σ = 449890222080. Its totient is φ = 151780629168.

The previous prime is 265666256497. The next prime is 265666256563. The reversal of 265666256541 is 145652666562.

It is a happy number.

It is not a de Polignac number, because 265666256541 - 2²⁵ = 265632702109 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (265666256641) 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, 891940 + ... + 1151906.

It is an arithmetic number, because the mean of its divisors is an integer number (14059069440).

Almost surely, 2^265666256541 is an apocalyptic number.

265666256541 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

265666256541 is a deficient number, since it is larger than the sum of its proper divisors (184223965539).

265666256541 is a wasteful number, since it uses less digits than its factorization.

265666256541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265390 (or 265384 counting only the distinct ones).

The product of its digits is 15552000, while the sum is 54.

The spelling of 265666256541 in words is "two hundred sixty-five billion, six hundred sixty-six million, two hundred fifty-six thousand, five hundred forty-one".