81335800220 has 96 divisors (see below), whose sum is σ = 182202628608. Its totient is φ = 30430363392.

The previous prime is 81335800199. The next prime is 81335800291. The reversal of 81335800220 is 2200853318.

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, 7479227 + ... + 7490093.

It is an arithmetic number, because the mean of its divisors is an integer number (1897944048).

Almost surely, 2^81335800220 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 81335800220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91101314304).

81335800220 is an abundant number, since it is smaller than the sum of its proper divisors (100866828388).

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

81335800220 is a wasteful number, since it uses less digits than its factorization.

81335800220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11259 (or 11257 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 32.

The spelling of 81335800220 in words is "eighty-one billion, three hundred thirty-five million, eight hundred thousand, two hundred twenty".