81588149240 has 128 divisors (see below), whose sum is σ = 200847911040. Its totient is φ = 29646176256.

The previous prime is 81588149239. The next prime is 81588149263. The reversal of 81588149240 is 4294188518.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19091744 + ... + 19096016.

It is an arithmetic number, because the mean of its divisors is an integer number (1569124305).

Almost surely, 2^81588149240 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 81588149240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100423955520).

81588149240 is an abundant number, since it is smaller than the sum of its proper divisors (119259761800).

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

81588149240 is a wasteful number, since it uses less digits than its factorization.

81588149240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4873 (or 4869 counting only the distinct ones).

The product of its (nonzero) digits is 737280, while the sum is 50.

The spelling of 81588149240 in words is "eighty-one billion, five hundred eighty-eight million, one hundred forty-nine thousand, two hundred forty".