665456938380 has 216 divisors, whose sum is σ = 2187127483632. Its totient is φ = 163703075328.

The previous prime is 665456938369. The next prime is 665456938409. The reversal of 665456938380 is 83839654566.

665456938380 is a `hidden beast` number, since 6 + 6 + 5 + 4 + 569 + 38 + 38 + 0 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 56788282 + ... + 56799998.

It is an arithmetic number, because the mean of its divisors is an integer number (10125590202).

Almost surely, 2^665456938380 is an apocalyptic number.

665456938380 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 665456938380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1093563741816).

665456938380 is an abundant number, since it is smaller than the sum of its proper divisors (1521670545252).

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

665456938380 is a wasteful number, since it uses less digits than its factorization.

665456938380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13625 (or 13607 counting only the distinct ones).

The product of its (nonzero) digits is 111974400, while the sum is 63.

The spelling of 665456938380 in words is "six hundred sixty-five billion, four hundred fifty-six million, nine hundred thirty-eight thousand, three hundred eighty".