81201415680 has 1920 divisors, whose sum is σ = 386625254400. Its totient is φ = 15765995520.

The previous prime is 81201415663. The next prime is 81201415697. The reversal of 81201415680 is 8651410218.

81201415680 is a `hidden beast` number, since 81 + 2 + 0 + 14 + 1 + 568 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (81201415663) and next prime (81201415697).

It is a tau number, because it is divible by the number of its divisors (1920).

It is a super-2 number, since 2×81201415680² (a number of 23 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 1112348124 + ... + 1112348196.

It is an arithmetic number, because the mean of its divisors is an integer number (201367320).

Almost surely, 2^81201415680 is an apocalyptic number.

81201415680 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 81201415680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (193312627200).

81201415680 is an abundant number, since it is smaller than the sum of its proper divisors (305423838720).

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

81201415680 is a wasteful number, since it uses less digits than its factorization.

81201415680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153 (or 120 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 36.

Adding to 81201415680 its reverse (8651410218), we get a palindrome (89852825898).

The spelling of 81201415680 in words is "eighty-one billion, two hundred one million, four hundred fifteen thousand, six hundred eighty".