64433456640 has 1280 divisors, whose sum is σ = 283467571200. Its totient is φ = 13544423424.

The previous prime is 64433456629. The next prime is 64433456671. The reversal of 64433456640 is 4665433446.

64433456640 is a `hidden beast` number, since 6 + 4 + 43 + 3 + 4 + 566 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (1280).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 395297199 + ... + 395297361.

It is an arithmetic number, because the mean of its divisors is an integer number (221459040).

Almost surely, 2^64433456640 is an apocalyptic number.

64433456640 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 64433456640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (141733785600).

64433456640 is an abundant number, since it is smaller than the sum of its proper divisors (219034114560).

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

64433456640 is a wasteful number, since it uses less digits than its factorization.

64433456640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 264 (or 242 counting only the distinct ones).

The product of its (nonzero) digits is 2488320, while the sum is 45.

The spelling of 64433456640 in words is "sixty-four billion, four hundred thirty-three million, four hundred fifty-six thousand, six hundred forty".