81585885120 has 56 divisors (see below), whose sum is σ = 259035188304. Its totient is φ = 21756235776.

The previous prime is 81585885113. The next prime is 81585885127. The reversal of 81585885120 is 2158858518.

It is an interprime number because it is at equal distance from previous prime (81585885113) and next prime (81585885127).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81585885127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42491689 + ... + 42493608.

Almost surely, 2^81585885120 is an apocalyptic number.

81585885120 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81585885120 is an abundant number, since it is smaller than the sum of its proper divisors (177449303184).

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

81585885120 is a wasteful number, since it uses less digits than its factorization.

81585885120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84985317 (or 84985307 counting only the distinct ones).

The product of its (nonzero) digits is 1024000, while the sum is 51.

The spelling of 81585885120 in words is "eighty-one billion, five hundred eighty-five million, eight hundred eighty-five thousand, one hundred twenty".