81884880 has 360 divisors, whose sum is σ = 350629344. Its totient is φ = 16934400.

The previous prime is 81884863. The next prime is 81884911. The reversal of 81884880 is 8848818.

It is a tau number, because it is divible by the number of its divisors (360).

It is a super-2 number, since 2×81884880² = 13410267145228800, which contains 22 as substring.

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 71 ways as a sum of consecutive naturals, for example, 387975 + ... + 388185.

Almost surely, 2^81884880 is an apocalyptic number.

81884880 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 81884880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (175314672).

81884880 is an abundant number, since it is smaller than the sum of its proper divisors (268744464).

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

81884880 is a wasteful number, since it uses less digits than its factorization.

81884880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255 (or 239 counting only the distinct ones).

The product of its (nonzero) digits is 131072, while the sum is 45.

The square root of 81884880 is about 9049.0264669742. The cubic root of 81884880 is about 434.2447457561.

The spelling of 81884880 in words is "eighty-one million, eight hundred eighty-four thousand, eight hundred eighty".