81640313210 has 64 divisors (see below), whose sum is σ = 156568204800. Its totient is φ = 30561772032.

The previous prime is 81640313207. The next prime is 81640313219. The reversal of 81640313210 is 1231304618.

It is not an unprimeable number, because it can be changed into a prime (81640313219) 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, 33362207 + ... + 33364653.

It is an arithmetic number, because the mean of its divisors is an integer number (2446378200).

Almost surely, 2^81640313210 is an apocalyptic number.

81640313210 is a deficient number, since it is larger than the sum of its proper divisors (74927891590).

81640313210 is a wasteful number, since it uses less digits than its factorization.

81640313210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4535.

The product of its (nonzero) digits is 3456, while the sum is 29.

Adding to 81640313210 its reverse (1231304618), we get a palindrome (82871617828).

The spelling of 81640313210 in words is "eighty-one billion, six hundred forty million, three hundred thirteen thousand, two hundred ten".