81869483520 has 480 divisors, whose sum is σ = 312307332480. Its totient is φ = 19655147520.

The previous prime is 81869483489. The next prime is 81869483539. The reversal of 81869483520 is 2538496818.

81869483520 is a `hidden beast` number, since 8 + 18 + 69 + 48 + 3 + 520 = 666.

It is a tau number, because it is divible by the number of its divisors (480).

It is a super-2 number, since 2×81869483520² (a number of 23 digits) contains 22 as substring.

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, 27116571 + ... + 27119589.

It is an arithmetic number, because the mean of its divisors is an integer number (650640276).

Almost surely, 2^81869483520 is an apocalyptic number.

81869483520 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 81869483520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (156153666240).

81869483520 is an abundant number, since it is smaller than the sum of its proper divisors (230437848960).

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

81869483520 is a wasteful number, since it uses less digits than its factorization.

81869483520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3166 (or 3147 counting only the distinct ones).

The product of its (nonzero) digits is 3317760, while the sum is 54.

The spelling of 81869483520 in words is "eighty-one billion, eight hundred sixty-nine million, four hundred eighty-three thousand, five hundred twenty".