68981576638464 has 840 divisors, whose sum is σ = 240186775567068. Its totient is φ = 19671184834560.

The previous prime is 68981576638453. The next prime is 68981576638517. The reversal of 68981576638464 is 46483667518986.

68981576638464 is a `hidden beast` number, since 6 + 8 + 9 + 8 + 1 + 576 + 6 + 38 + 4 + 6 + 4 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 51566646104064 + 17414930534400 = 7180992^2 + 4173120^2 .

It is a Harshad number since it is a multiple of its sum of digits (81).

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 19931109694 + ... + 19931113154.

Almost surely, 2^{68981576638464} is an apocalyptic number.

68981576638464 is a gapful number since it is divisible by the number (64) 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 68981576638464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120093387783534).

68981576638464 is an abundant number, since it is smaller than the sum of its proper divisors (171205198928604).

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

68981576638464 is an equidigital number, since it uses as much as digits as its factorization.

68981576638464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4126 (or 4086 counting only the distinct ones).

The product of its digits is 10032906240, while the sum is 81.

The spelling of 68981576638464 in words is "sixty-eight trillion, nine hundred eighty-one billion, five hundred seventy-six million, six hundred thirty-eight thousand, four hundred sixty-four".