81384408 has 96 divisors (see below), whose sum is σ = 254311200. Its totient is φ = 23030784.

The previous prime is 81384383. The next prime is 81384409. The reversal of 81384408 is 80448318.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81384409) 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, 56238 + ... + 57666.

It is an arithmetic number, because the mean of its divisors is an integer number (2649075).

Almost surely, 2^81384408 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 81384408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (127155600).

81384408 is an abundant number, since it is smaller than the sum of its proper divisors (172926792).

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

81384408 is a wasteful number, since it uses less digits than its factorization.

81384408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1561 (or 1554 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 36.

The square root of 81384408 is about 9021.3307222383. The cubic root of 81384408 is about 433.3582507697.

The spelling of 81384408 in words is "eighty-one million, three hundred eighty-four thousand, four hundred eight".