65643309385920 has 896 divisors, whose sum is σ = 266612424376320. Its totient is φ = 14893743144960.

The previous prime is 65643309385877. The next prime is 65643309385931. The reversal of 65643309385920 is 2958390334656.

65643309385920 is a `hidden beast` number, since 6 + 5 + 6 + 4 + 3 + 3 + 0 + 9 + 38 + 592 + 0 = 666.

It is a super-2 number, since 2×65643309385920² (a number of 28 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

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, 4620483457 + ... + 4620497663.

Almost surely, 2^{65643309385920} is an apocalyptic number.

65643309385920 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 65643309385920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133306212188160).

65643309385920 is an abundant number, since it is smaller than the sum of its proper divisors (200969114990400).

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

65643309385920 is a wasteful number, since it uses less digits than its factorization.

65643309385920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14798 (or 14782 counting only the distinct ones).

The product of its (nonzero) digits is 125971200, while the sum is 63.

The spelling of 65643309385920 in words is "sixty-five trillion, six hundred forty-three billion, three hundred nine million, three hundred eighty-five thousand, nine hundred twenty".