664637783040 has 792 divisors, whose sum is σ = 2893135146720. Its totient is φ = 138098442240.

The previous prime is 664637783011. The next prime is 664637783071. The reversal of 664637783040 is 40387736466.

It is a happy number.

664637783040 is a `hidden beast` number, since 66 + 463 + 7 + 7 + 83 + 0 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (792).

It is a super-2 number, since 2×664637783040² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 39021246 + ... + 39038274.

Almost surely, 2^664637783040 is an apocalyptic number.

664637783040 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 664637783040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1446567573360).

664637783040 is an abundant number, since it is smaller than the sum of its proper divisors (2228497363680).

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

664637783040 is a wasteful number, since it uses less digits than its factorization.

664637783040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17089 (or 17057 counting only the distinct ones).

The product of its (nonzero) digits is 12192768, while the sum is 54.

The spelling of 664637783040 in words is "six hundred sixty-four billion, six hundred thirty-seven million, seven hundred eighty-three thousand, forty".