665457408 has 432 divisors, whose sum is σ = 2489690112. Its totient is φ = 167270400.

The previous prime is 665457407. The next prime is 665457433. The reversal of 665457408 is 804754566.

665457408 is a `hidden beast` number, since 66 + 545 + 7 + 40 + 8 = 666.

It is not an unprimeable number, because it can be changed into a prime (665457407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 21466353 + ... + 21466383.

Almost surely, 2^665457408 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 665457408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1244845056).

665457408 is an abundant number, since it is smaller than the sum of its proper divisors (1824232704).

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

665457408 is a wasteful number, since it uses less digits than its factorization.

665457408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93 (or 54 counting only the distinct ones).

The product of its (nonzero) digits is 806400, while the sum is 45.

The square root of 665457408 is about 25796.4611526465. The cubic root of 665457408 is about 873.0519526795.

The spelling of 665457408 in words is "six hundred sixty-five million, four hundred fifty-seven thousand, four hundred eight".