81839206400 has 624 divisors, whose sum is σ = 249614499840. Its totient is φ = 26011238400.

The previous prime is 81839206399. The next prime is 81839206403. The reversal of 81839206400 is 460293818.

It is not an unprimeable number, because it can be changed into a prime (81839206403) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 644403137 + ... + 644403263.

Almost surely, 2^81839206400 is an apocalyptic number.

81839206400 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 81839206400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124807249920).

81839206400 is an abundant number, since it is smaller than the sum of its proper divisors (167775293440).

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

81839206400 is a wasteful number, since it uses less digits than its factorization.

81839206400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228 (or 201 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 41.

The spelling of 81839206400 in words is "eighty-one billion, eight hundred thirty-nine million, two hundred six thousand, four hundred".