81623400 has 96 divisors (see below), whose sum is σ = 261813600. Its totient is φ = 21011200.

The previous prime is 81623383. The next prime is 81623401. The reversal of 81623400 is 432618.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (81623401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15055 + ... + 19745.

It is an arithmetic number, because the mean of its divisors is an integer number (2727225).

Almost surely, 2^81623400 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81623400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (130906800).

81623400 is an abundant number, since it is smaller than the sum of its proper divisors (180190200).

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

81623400 is a wasteful number, since it uses less digits than its factorization.

81623400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4739 (or 4730 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 81623400 is about 9034.5669514371. The cubic root of 81623400 is about 433.7820335839.

The spelling of 81623400 in words is "eighty-one million, six hundred twenty-three thousand, four hundred".