665541593838 has 96 divisors (see below), whose sum is σ = 1588109608800. Its totient is φ = 199756108800.

The previous prime is 665541593833. The next prime is 665541593887. The reversal of 665541593838 is 838395145566.

It is a happy number.

665541593838 is a `hidden beast` number, since 6 + 6 + 5 + 5 + 4 + 1 + 593 + 8 + 38 = 666.

It is a super-2 number, since 2×665541593838² (a number of 24 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665541593833) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 102058018 + ... + 102064538.

It is an arithmetic number, because the mean of its divisors is an integer number (16542808425).

Almost surely, 2^665541593838 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 665541593838, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (794054804400).

665541593838 is an abundant number, since it is smaller than the sum of its proper divisors (922568014962).

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

665541593838 is a wasteful number, since it uses less digits than its factorization.

665541593838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11378 (or 11375 counting only the distinct ones).

The product of its digits is 93312000, while the sum is 63.

The spelling of 665541593838 in words is "six hundred sixty-five billion, five hundred forty-one million, five hundred ninety-three thousand, eight hundred thirty-eight".