81913477720704 has 128 divisors (see below), whose sum is σ = 252377346624000. Its totient is φ = 23054539521024.

The previous prime is 81913477720693. The next prime is 81913477720757. The reversal of 81913477720704 is 40702777431918.

It is a tau number, because it is divible by the number of its divisors (128).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 227236054 + ... + 227596245.

It is an arithmetic number, because the mean of its divisors is an integer number (1971698020500).

Almost surely, 2^{81913477720704} is an apocalyptic number.

81913477720704 is a gapful number since it is divisible by the number (84) formed by its first and last digit.

It is an amenable number.

81913477720704 is an abundant number, since it is smaller than the sum of its proper divisors (170463868903296).

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

81913477720704 is a wasteful number, since it uses less digits than its factorization.

81913477720704 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 454832390 (or 454832378 counting only the distinct ones).

The product of its (nonzero) digits is 16595712, while the sum is 60.

The spelling of 81913477720704 in words is "eighty-one trillion, nine hundred thirteen billion, four hundred seventy-seven million, seven hundred twenty thousand, seven hundred four".