81284160 has 112 divisors (see below), whose sum is σ = 259909056. Its totient is φ = 21522432.

The previous prime is 81284143. The next prime is 81284167. The reversal of 81284160 is 6148218.

It is a super-2 number, since 2×81284160² = 13214229333811200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (81284167) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 217734 + ... + 218106.

Almost surely, 2^81284160 is an apocalyptic number.

81284160 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 81284160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (129954528).

81284160 is an abundant number, since it is smaller than the sum of its proper divisors (178624896).

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

81284160 is a wasteful number, since it uses less digits than its factorization.

81284160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 620 (or 610 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 30.

The square root of 81284160 is about 9015.7728454082. The cubic root of 81284160 is about 433.1802430948.

The spelling of 81284160 in words is "eighty-one million, two hundred eighty-four thousand, one hundred sixty".