81588505460 has 144 divisors (see below), whose sum is σ = 224926450560. Its totient is φ = 24553186560.

The previous prime is 81588505447. The next prime is 81588505507. The reversal of 81588505460 is 6450588518.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 81588505399 and 81588505408.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 182129 + ... + 443111.

It is an arithmetic number, because the mean of its divisors is an integer number (1561989240).

Almost surely, 2^81588505460 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 81588505460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112463225280).

81588505460 is an abundant number, since it is smaller than the sum of its proper divisors (143337945100).

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

81588505460 is a wasteful number, since it uses less digits than its factorization.

81588505460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 261046 (or 261037 counting only the distinct ones).

The product of its (nonzero) digits is 1536000, while the sum is 50.

The spelling of 81588505460 in words is "eighty-one billion, five hundred eighty-eight million, five hundred five thousand, four hundred sixty".