81214986720 has 768 divisors, whose sum is σ = 319328593920. Its totient is φ = 16930308096.

The previous prime is 81214986719. The next prime is 81214986767. The reversal of 81214986720 is 2768941218.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 81214986720.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 420802944 + ... + 420803136.

It is an arithmetic number, because the mean of its divisors is an integer number (415792440).

Almost surely, 2^81214986720 is an apocalyptic number.

81214986720 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 81214986720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (159664296960).

81214986720 is an abundant number, since it is smaller than the sum of its proper divisors (238113607200).

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

81214986720 is a wasteful number, since it uses less digits than its factorization.

81214986720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 427 (or 419 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 48.

It can be divided in two parts, 8121498 and 6720, that added together give a palindrome (8128218).

The spelling of 81214986720 in words is "eighty-one billion, two hundred fourteen million, nine hundred eighty-six thousand, seven hundred twenty".