81646063809970 has 64 divisors (see below), whose sum is σ = 166361362071552. Its totient is φ = 28581324408000.

The previous prime is 81646063809967. The next prime is 81646063809979. The reversal of 81646063809970 is 7990836064618.

It is a Smith number, since the sum of its digits (67) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 81646063809896 and 81646063809905.

It is not an unprimeable number, because it can be changed into a prime (81646063809979) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 62027034 + ... + 63329653.

It is an arithmetic number, because the mean of its divisors is an integer number (2599396282368).

Almost surely, 2^{81646063809970} is an apocalyptic number.

81646063809970 is an abundant number, since it is smaller than the sum of its proper divisors (84715298261582).

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

81646063809970 is a wasteful number, since it uses less digits than its factorization.

81646063809970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125356927.

The product of its (nonzero) digits is 94058496, while the sum is 67.

The spelling of 81646063809970 in words is "eighty-one trillion, six hundred forty-six billion, sixty-three million, eight hundred nine thousand, nine hundred seventy".