81083978880 has 256 divisors, whose sum is σ = 267913820160. Its totient is φ = 20844933120.

The previous prime is 81083978869. The next prime is 81083978881. The reversal of 81083978880 is 8887938018.

It is a super-2 number, since 2×81083978880² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is not an unprimeable number, because it can be changed into a prime (81083978881) 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, 6039375 + ... + 6052785.

It is an arithmetic number, because the mean of its divisors is an integer number (1046538360).

Almost surely, 2^81083978880 is an apocalyptic number.

81083978880 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 81083978880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133956910080).

81083978880 is an abundant number, since it is smaller than the sum of its proper divisors (186829841280).

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

81083978880 is a wasteful number, since it uses less digits than its factorization.

81083978880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13547 (or 13535 counting only the distinct ones).

The product of its (nonzero) digits is 6193152, while the sum is 60.

The spelling of 81083978880 in words is "eighty-one billion, eighty-three million, nine hundred seventy-eight thousand, eight hundred eighty".