81344037888 has 176 divisors, whose sum is σ = 253582360000. Its totient is φ = 25687425024.

The previous prime is 81344037857. The next prime is 81344037889. The reversal of 81344037888 is 88873044318.

It is a happy number.

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

It is not an unprimeable number, because it can be changed into a prime (81344037889) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 447888 + ... + 602736.

Almost surely, 2^81344037888 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81344037888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (126791180000).

81344037888 is an abundant number, since it is smaller than the sum of its proper divisors (172238322112).

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

81344037888 is a wasteful number, since it uses less digits than its factorization.

81344037888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154897 (or 154873 counting only the distinct ones).

The product of its (nonzero) digits is 4128768, while the sum is 54.

Adding to 81344037888 its product of nonzero digits (4128768), we get a square (81348166656 = 285216²).

The spelling of 81344037888 in words is "eighty-one billion, three hundred forty-four million, thirty-seven thousand, eight hundred eighty-eight".