64673072640 has 240 divisors, whose sum is σ = 244343910096. Its totient is φ = 15678259200.

The previous prime is 64673072623. The next prime is 64673072669. The reversal of 64673072640 is 4627037646.

It is a tau number, because it is divible by the number of its divisors (240).

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 23 ways as a sum of consecutive naturals, for example, 125850 + ... + 381030.

Almost surely, 2^64673072640 is an apocalyptic number.

64673072640 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 64673072640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (122171955048).

64673072640 is an abundant number, since it is smaller than the sum of its proper divisors (179670837456).

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

64673072640 is a wasteful number, since it uses less digits than its factorization.

64673072640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255221 (or 255202 counting only the distinct ones).

The product of its (nonzero) digits is 1016064, while the sum is 45.

The spelling of 64673072640 in words is "sixty-four billion, six hundred seventy-three million, seventy-two thousand, six hundred forty".