81846145920 has 512 divisors, whose sum is σ = 332207308800. Its totient is φ = 16643727360.

The previous prime is 81846145903. The next prime is 81846145921. The reversal of 81846145920 is 2954164818.

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

It is a self number, because there is not a number n which added to its sum of digits gives 81846145920.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81846145921) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 6942591 + ... + 6954369.

It is an arithmetic number, because the mean of its divisors is an integer number (648842400).

Almost surely, 2^81846145920 is an apocalyptic number.

81846145920 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 81846145920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (166103654400).

81846145920 is an abundant number, since it is smaller than the sum of its proper divisors (250361162880).

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

81846145920 is a wasteful number, since it uses less digits than its factorization.

81846145920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11866 (or 11854 counting only the distinct ones).

The product of its (nonzero) digits is 552960, while the sum is 48.

The spelling of 81846145920 in words is "eighty-one billion, eight hundred forty-six million, one hundred forty-five thousand, nine hundred twenty".