81025124048640 has 432 divisors, whose sum is σ = 290758839815808. Its totient is φ = 21603917058048.

The previous prime is 81025124048599. The next prime is 81025124048651. The reversal of 81025124048640 is 4684042152018.

81025124048640 is a `hidden beast` number, since 8 + 1 + 0 + 2 + 5 + 124 + 0 + 486 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (432).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3795610447 + ... + 3795631793.

It is an arithmetic number, because the mean of its divisors is an integer number (673052869944).

Almost surely, 2^{81025124048640} is an apocalyptic number.

81025124048640 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 81025124048640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145379419907904).

81025124048640 is an abundant number, since it is smaller than the sum of its proper divisors (209733715767168).

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

81025124048640 is a wasteful number, since it uses less digits than its factorization.

81025124048640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33586 (or 33560 counting only the distinct ones).

The product of its (nonzero) digits is 491520, while the sum is 45.

The spelling of 81025124048640 in words is "eighty-one trillion, twenty-five billion, one hundred twenty-four million, forty-eight thousand, six hundred forty".