81828560 has 40 divisors (see below), whose sum is σ = 207549216. Its totient is φ = 29755520.

The previous prime is 81828553. The next prime is 81828563. The reversal of 81828560 is 6582818.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81828563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45614 + ... + 47373.

Almost surely, 2^81828560 is an apocalyptic number.

81828560 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81828560 is an abundant number, since it is smaller than the sum of its proper divisors (125720656).

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

81828560 is a wasteful number, since it uses less digits than its factorization.

81828560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93011 (or 93005 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 38.

The square root of 81828560 is about 9045.9139947271. The cubic root of 81828560 is about 434.1451658203.

The spelling of 81828560 in words is "eighty-one million, eight hundred twenty-eight thousand, five hundred sixty".