81870808320 has 360 divisors, whose sum is σ = 334801509504. Its totient is φ = 18713161728.

The previous prime is 81870808291. The next prime is 81870808333. The reversal of 81870808320 is 2380807818.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (360).

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 39 ways as a sum of consecutive naturals, for example, 669357 + ... + 782163.

Almost surely, 2^81870808320 is an apocalyptic number.

81870808320 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 81870808320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (167400754752).

81870808320 is an abundant number, since it is smaller than the sum of its proper divisors (252930701184).

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

81870808320 is a wasteful number, since it uses less digits than its factorization.

81870808320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112847 (or 112824 counting only the distinct ones).

The product of its (nonzero) digits is 172032, while the sum is 45.

The spelling of 81870808320 in words is "eighty-one billion, eight hundred seventy million, eight hundred eight thousand, three hundred twenty".