81758637200 has 60 divisors (see below), whose sum is σ = 207979562340. Its totient is φ = 30779719680.

The previous prime is 81758637199. The next prime is 81758637227. The reversal of 81758637200 is 273685718.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 8808948736 + 72949688464 = 93856^2 + 270092^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6004865 + ... + 6018464.

It is an arithmetic number, because the mean of its divisors is an integer number (3466326039).

Almost surely, 2^81758637200 is an apocalyptic number.

81758637200 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81758637200 is an abundant number, since it is smaller than the sum of its proper divisors (126220925140).

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

81758637200 is a wasteful number, since it uses less digits than its factorization.

81758637200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12023364 (or 12023353 counting only the distinct ones).

The product of its (nonzero) digits is 564480, while the sum is 47.

The spelling of 81758637200 in words is "eighty-one billion, seven hundred fifty-eight million, six hundred thirty-seven thousand, two hundred".