81465600 has 108 divisors (see below), whose sum is σ = 268916816. Its totient is φ = 21719040.

The previous prime is 81465599. The next prime is 81465641. The reversal of 81465600 is 656418.

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

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17079 + ... + 21321.

Almost surely, 2^81465600 is an apocalyptic number.

81465600 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 81465600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (134458408).

81465600 is an abundant number, since it is smaller than the sum of its proper divisors (187451216).

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

81465600 is a wasteful number, since it uses less digits than its factorization.

81465600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4272 (or 4253 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 81465600 is about 9025.8296017596. The cubic root of 81465600 is about 433.5023141096.

The spelling of 81465600 in words is "eighty-one million, four hundred sixty-five thousand, six hundred".