81610283520 has 480 divisors, whose sum is σ = 304838614080. Its totient is φ = 20110049280.

The previous prime is 81610283519. The next prime is 81610283549. The reversal of 81610283520 is 2538201618.

It is a happy number.

81610283520 is a `hidden beast` number, since 8 + 1 + 610 + 2 + 8 + 35 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 17945887 + ... + 17950433.

It is an arithmetic number, because the mean of its divisors is an integer number (635080446).

Almost surely, 2^81610283520 is an apocalyptic number.

81610283520 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 81610283520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (152419307040).

81610283520 is an abundant number, since it is smaller than the sum of its proper divisors (223228330560).

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

81610283520 is a wasteful number, since it uses less digits than its factorization.

81610283520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4636 (or 4617 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The spelling of 81610283520 in words is "eighty-one billion, six hundred ten million, two hundred eighty-three thousand, five hundred twenty".