265633666221 has 48 divisors (see below), whose sum is σ = 449561484288. Its totient is φ = 137959768800.

The previous prime is 265633666183. The next prime is 265633666231. The reversal of 265633666221 is 122666336562.

It is a happy number.

It is not a de Polignac number, because 265633666221 - 2²² = 265629471917 is a prime.

It is a super-2 number, since 2×265633666221² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (265633666231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 8086396 + ... + 8119178.

It is an arithmetic number, because the mean of its divisors is an integer number (9365864256).

Almost surely, 2^265633666221 is an apocalyptic number.

265633666221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

265633666221 is a deficient number, since it is larger than the sum of its proper divisors (183927818067).

265633666221 is a wasteful number, since it uses less digits than its factorization.

265633666221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37822 (or 37815 counting only the distinct ones).

The product of its digits is 2799360, while the sum is 48.

The spelling of 265633666221 in words is "two hundred sixty-five billion, six hundred thirty-three million, six hundred sixty-six thousand, two hundred twenty-one".