81442037600 has 432 divisors, whose sum is σ = 256162979520. Its totient is φ = 24996787200.

The previous prime is 81442037591. The next prime is 81442037641. The reversal of 81442037600 is 673024418.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 28888991 + ... + 28891809.

It is an arithmetic number, because the mean of its divisors is an integer number (592969860).

Almost surely, 2^81442037600 is an apocalyptic number.

81442037600 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 81442037600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128081489760).

81442037600 is an abundant number, since it is smaller than the sum of its proper divisors (174720941920).

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

81442037600 is a wasteful number, since it uses less digits than its factorization.

81442037600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2931 (or 2911 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 35.

The spelling of 81442037600 in words is "eighty-one billion, four hundred forty-two million, thirty-seven thousand, six hundred".