81246644780 has 48 divisors (see below), whose sum is σ = 195020749056. Its totient is φ = 27851878080.

The previous prime is 81246644771. The next prime is 81246644813. The reversal of 81246644780 is 8744664218.

It is a happy number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 998387 + ... + 1076693.

It is an arithmetic number, because the mean of its divisors is an integer number (4062932272).

Almost surely, 2^81246644780 is an apocalyptic number.

It is an amenable number.

81246644780 is an abundant number, since it is smaller than the sum of its proper divisors (113774104276).

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

81246644780 is a wasteful number, since it uses less digits than its factorization.

81246644780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85734 (or 85732 counting only the distinct ones).

The product of its (nonzero) digits is 2064384, while the sum is 50.

The spelling of 81246644780 in words is "eighty-one billion, two hundred forty-six million, six hundred forty-four thousand, seven hundred eighty".