81225878160 has 320 divisors, whose sum is σ = 300858458112. Its totient is φ = 17724715008.

The previous prime is 81225878143. The next prime is 81225878191. The reversal of 81225878160 is 6187852218.

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

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 23839177 + ... + 23842583.

Almost surely, 2^81225878160 is an apocalyptic number.

81225878160 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 81225878160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (150429229056).

81225878160 is an abundant number, since it is smaller than the sum of its proper divisors (219632579952).

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

81225878160 is a wasteful number, since it uses less digits than its factorization.

81225878160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4070 (or 4064 counting only the distinct ones).

The product of its (nonzero) digits is 430080, while the sum is 48.

The spelling of 81225878160 in words is "eighty-one billion, two hundred twenty-five million, eight hundred seventy-eight thousand, one hundred sixty".