81761746809600 has 3240 divisors, whose sum is σ = 366925006202832. Its totient is φ = 17794075852800.

The previous prime is 81761746809593. The next prime is 81761746809601. The reversal of 81761746809600 is 690864716718.

81761746809600 is a `hidden beast` number, since 8 + 1 + 7 + 6 + 17 + 4 + 6 + 8 + 0 + 9 + 600 = 666.

It is a tau number, because it is divible by the number of its divisors (3240).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81761746809601) by changing a digit.

It is a polite number, since it can be written in 359 ways as a sum of consecutive naturals, for example, 35657106054 + ... + 35657108346.

Almost surely, 2^{81761746809600} is an apocalyptic number.

81761746809600 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81761746809600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (183462503101416).

81761746809600 is an abundant number, since it is smaller than the sum of its proper divisors (285163259393232).

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

81761746809600 is a wasteful number, since it uses less digits than its factorization.

81761746809600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2405 (or 2364 counting only the distinct ones).

The product of its (nonzero) digits is 24385536, while the sum is 63.

The spelling of 81761746809600 in words is "eighty-one trillion, seven hundred sixty-one billion, seven hundred forty-six million, eight hundred nine thousand, six hundred".