64649639658240 has 1728 divisors, whose sum is σ = 286012987932672. Its totient is φ = 13115237990400.

The previous prime is 64649639658199. The next prime is 64649639658251. The reversal of 64649639658240 is 4285693694646.

64649639658240 is a `hidden beast` number, since 6 + 4 + 6 + 4 + 9 + 6 + 39 + 6 + 582 + 4 + 0 = 666.

It is a super-3 number, since 3×64649639658240³ (a number of 42 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (72) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 5102167105 + ... + 5102179775.

It is an arithmetic number, because the mean of its divisors is an integer number (165516775424).

Almost surely, 2^{64649639658240} is an apocalyptic number.

64649639658240 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 64649639658240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (143006493966336).

64649639658240 is an abundant number, since it is smaller than the sum of its proper divisors (221363348274432).

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

64649639658240 is a wasteful number, since it uses less digits than its factorization.

64649639658240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12906 (or 12889 counting only the distinct ones).

The product of its (nonzero) digits is 1612431360, while the sum is 72.

The spelling of 64649639658240 in words is "sixty-four trillion, six hundred forty-nine billion, six hundred thirty-nine million, six hundred fifty-eight thousand, two hundred forty".