81423360 has 352 divisors, whose sum is σ = 314419200. Its totient is φ = 19906560.

The previous prime is 81423337. The next prime is 81423361. The reversal of 81423360 is 6332418.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81423361) 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, 2626545 + ... + 2626575.

Almost surely, 2^81423360 is an apocalyptic number.

81423360 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 81423360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (157209600).

81423360 is an abundant number, since it is smaller than the sum of its proper divisors (232995840).

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

81423360 is a wasteful number, since it uses less digits than its factorization.

81423360 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84 (or 60 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 81423360 is about 9023.4893472536. The cubic root of 81423360 is about 433.4273773533.

Adding to 81423360 its reverse (6332418), we get a palindrome (87755778).

The spelling of 81423360 in words is "eighty-one million, four hundred twenty-three thousand, three hundred sixty".