81649403108 has 24 divisors (see below), whose sum is σ = 175860253632. Its totient is φ = 32300862624.

The previous prime is 81649403107. The next prime is 81649403117. The reversal of 81649403108 is 80130494618.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (81649403107) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 112155410 + ... + 112156137.

It is an arithmetic number, because the mean of its divisors is an integer number (7327510568).

Almost surely, 2^81649403108 is an apocalyptic number.

It is an amenable number.

81649403108 is an abundant number, since it is smaller than the sum of its proper divisors (94210850524).

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

81649403108 is a wasteful number, since it uses less digits than its factorization.

81649403108 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224311571 (or 224311569 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 44.

The spelling of 81649403108 in words is "eighty-one billion, six hundred forty-nine million, four hundred three thousand, one hundred eight".