81894758400 has 2160 divisors, whose sum is σ = 392241769920. Its totient is φ = 16721510400.

The previous prime is 81894758377. The next prime is 81894758483. The reversal of 81894758400 is 485749818.

81894758400 is a `hidden beast` number, since 8 + 18 + 9 + 47 + 584 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (2160).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 179 ways as a sum of consecutive naturals, for example, 2641766385 + ... + 2641766415.

It is an arithmetic number, because the mean of its divisors is an integer number (181593412).

Almost surely, 2^81894758400 is an apocalyptic number.

81894758400 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 81894758400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (196120884960).

81894758400 is an abundant number, since it is smaller than the sum of its proper divisors (310347011520).

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

81894758400 is a wasteful number, since it uses less digits than its factorization.

81894758400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102 (or 61 counting only the distinct ones).

The product of its (nonzero) digits is 2580480, while the sum is 54.

The spelling of 81894758400 in words is "eighty-one billion, eight hundred ninety-four million, seven hundred fifty-eight thousand, four hundred".