81593450400 has 288 divisors, whose sum is σ = 331121806848. Its totient is φ = 16954444800.

The previous prime is 81593450333. The next prime is 81593450401. The reversal of 81593450400 is 405439518.

It is a super-2 number, since 2×81593450400² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81593450401) 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, 35962 + ... + 405561.

It is an arithmetic number, because the mean of its divisors is an integer number (1149728496).

Almost surely, 2^81593450400 is an apocalyptic number.

81593450400 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 81593450400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (165560903424).

81593450400 is an abundant number, since it is smaller than the sum of its proper divisors (249528356448).

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

81593450400 is a wasteful number, since it uses less digits than its factorization.

81593450400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 441564 (or 441551 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 39.

Adding to 81593450400 its reverse (405439518), we get a palindrome (81998889918).

The spelling of 81593450400 in words is "eighty-one billion, five hundred ninety-three million, four hundred fifty thousand, four hundred".