665415381888 has 256 divisors, whose sum is σ = 1995598176000. Its totient is φ = 218233128960.

The previous prime is 665415381877. The next prime is 665415381899. The reversal of 665415381888 is 888183514566.

665415381888 is a `hidden beast` number, since 6 + 6 + 5 + 4 + 1 + 538 + 18 + 88 = 666.

It is an interprime number because it is at equal distance from previous prime (665415381877) and next prime (665415381899).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 330886803 + ... + 330888813.

It is an arithmetic number, because the mean of its divisors is an integer number (7795305375).

Almost surely, 2^665415381888 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 665415381888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (997799088000).

665415381888 is an abundant number, since it is smaller than the sum of its proper divisors (1330182794112).

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

665415381888 is a wasteful number, since it uses less digits than its factorization.

665415381888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3530 (or 3512 counting only the distinct ones).

The product of its digits is 44236800, while the sum is 63.

The spelling of 665415381888 in words is "six hundred sixty-five billion, four hundred fifteen million, three hundred eighty-one thousand, eight hundred eighty-eight".