81479623680 has 1760 divisors, whose sum is σ = 383490809856. Its totient is φ = 16052649984.

The previous prime is 81479623661. The next prime is 81479623739. The reversal of 81479623680 is 8632697418.

81479623680 is a `hidden beast` number, since 8 + 1 + 4 + 7 + 9 + 623 + 6 + 8 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 641571777 + ... + 641571903.

Almost surely, 2^81479623680 is an apocalyptic number.

81479623680 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 81479623680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (191745404928).

81479623680 is an abundant number, since it is smaller than the sum of its proper divisors (302011186176).

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

81479623680 is a wasteful number, since it uses less digits than its factorization.

81479623680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201 (or 174 counting only the distinct ones).

The product of its (nonzero) digits is 3483648, while the sum is 54.

The spelling of 81479623680 in words is "eighty-one billion, four hundred seventy-nine million, six hundred twenty-three thousand, six hundred eighty".