81436913760 has 192 divisors, whose sum is σ = 265627615680. Its totient is φ = 20947476480.

The previous prime is 81436913759. The next prime is 81436913801. The reversal of 81436913760 is 6731963418.

It is a happy number.

It is a hoax number, since the sum of its digits (48) coincides with the sum of the digits of its distinct prime factors.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19110030 + ... + 19114290.

It is an arithmetic number, because the mean of its divisors is an integer number (1383477165).

Almost surely, 2^81436913760 is an apocalyptic number.

81436913760 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 81436913760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (132813807840).

81436913760 is an abundant number, since it is smaller than the sum of its proper divisors (184190701920).

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

81436913760 is a wasteful number, since it uses less digits than its factorization.

81436913760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5681 (or 5673 counting only the distinct ones).

The product of its (nonzero) digits is 653184, while the sum is 48.

The spelling of 81436913760 in words is "eighty-one billion, four hundred thirty-six million, nine hundred thirteen thousand, seven hundred sixty".