81412320 has 192 divisors, whose sum is σ = 296545536. Its totient is φ = 18554880.

The previous prime is 81412313. The next prime is 81412327. The reversal of 81412320 is 2321418.

It is an interprime number because it is at equal distance from previous prime (81412313) and next prime (81412327).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81412327) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 89307 + ... + 90213.

It is an arithmetic number, because the mean of its divisors is an integer number (1544508).

Almost surely, 2^81412320 is an apocalyptic number.

81412320 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 81412320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (148272768).

81412320 is an abundant number, since it is smaller than the sum of its proper divisors (215133216).

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

81412320 is a wasteful number, since it uses less digits than its factorization.

81412320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 953 (or 945 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 81412320 is about 9022.8775897715. The cubic root of 81412320 is about 433.4077873383.

Adding to 81412320 its reverse (2321418), we get a palindrome (83733738).

The spelling of 81412320 in words is "eighty-one million, four hundred twelve thousand, three hundred twenty".