81867202560 has 672 divisors, whose sum is σ = 333617120928. Its totient is φ = 18308136960.

The previous prime is 81867202523. The next prime is 81867202597. The reversal of 81867202560 is 6520276818.

81867202560 is a `hidden beast` number, since 8 + 1 + 8 + 67 + 20 + 2 + 560 = 666.

It is an interprime number because it is at equal distance from previous prime (81867202523) and next prime (81867202597).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 52714744 + ... + 52716296.

It is an arithmetic number, because the mean of its divisors is an integer number (496454049).

Almost surely, 2^81867202560 is an apocalyptic number.

81867202560 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 81867202560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (166808560464).

81867202560 is an abundant number, since it is smaller than the sum of its proper divisors (251749918368).

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

81867202560 is a wasteful number, since it uses less digits than its factorization.

81867202560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1614 (or 1587 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 45.

The spelling of 81867202560 in words is "eighty-one billion, eight hundred sixty-seven million, two hundred two thousand, five hundred sixty".