665133081426 has 192 divisors, whose sum is σ = 1694372359680. Its totient is φ = 186332590080.

The previous prime is 665133081419. The next prime is 665133081439. The reversal of 665133081426 is 624180331566.

665133081426 is a `hidden beast` number, since 6 + 6 + 513 + 30 + 81 + 4 + 26 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 52378710 + ... + 52391406.

It is an arithmetic number, because the mean of its divisors is an integer number (8824856040).

Almost surely, 2^665133081426 is an apocalyptic number.

665133081426 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 665133081426, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (847186179840).

665133081426 is an abundant number, since it is smaller than the sum of its proper divisors (1029239278254).

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

665133081426 is a wasteful number, since it uses less digits than its factorization.

665133081426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13009 (or 13006 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 45.

The spelling of 665133081426 in words is "six hundred sixty-five billion, one hundred thirty-three million, eighty-one thousand, four hundred twenty-six".