81677128560 has 160 divisors (see below), whose sum is σ = 267491688960. Its totient is φ = 20559412224.

The previous prime is 81677128543. The next prime is 81677128597. The reversal of 81677128560 is 6582177618.

It is a happy number.

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, 1230789 + ... + 1295451.

It is an arithmetic number, because the mean of its divisors is an integer number (1671823056).

Almost surely, 2^81677128560 is an apocalyptic number.

81677128560 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 81677128560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133745844480).

81677128560 is an abundant number, since it is smaller than the sum of its proper divisors (185814560400).

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

81677128560 is a wasteful number, since it uses less digits than its factorization.

81677128560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64975 (or 64969 counting only the distinct ones).

The product of its (nonzero) digits is 1128960, while the sum is 51.

The spelling of 81677128560 in words is "eighty-one billion, six hundred seventy-seven million, one hundred twenty-eight thousand, five hundred sixty".