81325054355520 has 448 divisors, whose sum is σ = 266161933877760. Its totient is φ = 21028375560192.

The previous prime is 81325054355491. The next prime is 81325054355659. The reversal of 81325054355520 is 2555345052318.

It is a super-2 number, since 2×81325054355520² (a number of 29 digits) contains 22 as substring.

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

It is a self number, because there is not a number n which added to its sum of digits gives 81325054355520.

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, 16406100882 + ... + 16406105838.

Almost surely, 2^{81325054355520} is an apocalyptic number.

81325054355520 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 81325054355520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133080966938880).

81325054355520 is an abundant number, since it is smaller than the sum of its proper divisors (184836879522240).

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

81325054355520 is a wasteful number, since it uses less digits than its factorization.

81325054355520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8742 (or 8732 counting only the distinct ones).

The product of its (nonzero) digits is 3600000, while the sum is 48.

The spelling of 81325054355520 in words is "eighty-one trillion, three hundred twenty-five billion, fifty-four million, three hundred fifty-five thousand, five hundred twenty".