81354426663744 has 560 divisors, whose sum is σ = 278861228464896. Its totient is φ = 23227803648000.

The previous prime is 81354426663709. The next prime is 81354426663823. The reversal of 81354426663744 is 44736662445318.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 80842069 + ... + 81842219.

Almost surely, 2^{81354426663744} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81354426663744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (139430614232448).

81354426663744 is an abundant number, since it is smaller than the sum of its proper divisors (197506801801152).

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

81354426663744 is a wasteful number, since it uses less digits than its factorization.

81354426663744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1000276 (or 1000257 counting only the distinct ones).

The product of its digits is 278691840, while the sum is 63.

The spelling of 81354426663744 in words is "eighty-one trillion, three hundred fifty-four billion, four hundred twenty-six million, six hundred sixty-three thousand, seven hundred forty-four".