81008380 has 24 divisors (see below), whose sum is σ = 173329632. Its totient is φ = 31791552.

The previous prime is 81008377. The next prime is 81008387. The reversal of 81008380 is 8380018.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81008387) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37152 + ... + 39271.

It is an arithmetic number, because the mean of its divisors is an integer number (7222068).

Almost surely, 2^81008380 is an apocalyptic number.

It is an amenable number.

81008380 is an abundant number, since it is smaller than the sum of its proper divisors (92321252).

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

81008380 is a wasteful number, since it uses less digits than its factorization.

81008380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76485 (or 76483 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 28.

The square root of 81008380 is about 9000.4655435150. The cubic root of 81008380 is about 432.6897916288.

Adding to 81008380 its reverse (8380018), we get a palindrome (89388398).

The spelling of 81008380 in words is "eighty-one million, eight thousand, three hundred eighty".