81253921029120 has 1408 divisors, whose sum is σ = 337563471544320. Its totient is φ = 18379137613824.

The previous prime is 81253921029059. The next prime is 81253921029121. The reversal of 81253921029120 is 2192012935218.

81253921029120 is a `hidden beast` number, since 8 + 1 + 2 + 539 + 2 + 1 + 0 + 2 + 91 + 20 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81253921029121) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 7603056417 + ... + 7603067103.

Almost surely, 2^{81253921029120} is an apocalyptic number.

81253921029120 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 81253921029120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (168781735772160).

81253921029120 is an abundant number, since it is smaller than the sum of its proper divisors (256309550515200).

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

81253921029120 is an equidigital number, since it uses as much as digits as its factorization.

81253921029120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10837 (or 10801 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 45.

The spelling of 81253921029120 in words is "eighty-one trillion, two hundred fifty-three billion, nine hundred twenty-one million, twenty-nine thousand, one hundred twenty".