81305924080 has 40 divisors (see below), whose sum is σ = 189094919472. Its totient is φ = 32512280064.

The previous prime is 81305924047. The next prime is 81305924083. The reversal of 81305924080 is 8042950318.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×81305924080² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81305924083) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 104539 + ... + 416581.

Almost surely, 2^81305924080 is an apocalyptic number.

81305924080 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81305924080 is an abundant number, since it is smaller than the sum of its proper divisors (107788995392).

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

81305924080 is a wasteful number, since it uses less digits than its factorization.

81305924080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 315313 (or 315307 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 40.

The spelling of 81305924080 in words is "eighty-one billion, three hundred five million, nine hundred twenty-four thousand, eighty".