81438796518068 has 576 divisors, whose sum is σ = 175322249625600. Its totient is φ = 32959851724800.

The previous prime is 81438796518067. The next prime is 81438796518071. The reversal of 81438796518068 is 86081569783418.

It is a super-2 number, since 2×81438796518068² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81438796517986 and 81438796518004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81438796518067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 316882476596 + ... + 316882476852.

It is an arithmetic number, because the mean of its divisors is an integer number (304378905600).

Almost surely, 2^{81438796518068} is an apocalyptic number.

It is an amenable number.

81438796518068 is an abundant number, since it is smaller than the sum of its proper divisors (93883453107532).

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

81438796518068 is a wasteful number, since it uses less digits than its factorization.

81438796518068 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 652 (or 639 counting only the distinct ones).

The product of its (nonzero) digits is 557383680, while the sum is 74.

The spelling of 81438796518068 in words is "eighty-one trillion, four hundred thirty-eight billion, seven hundred ninety-six million, five hundred eighteen thousand, sixty-eight".