81054820 has 144 divisors (see below), whose sum is σ = 221090688. Its totient is φ = 24675840.

The previous prime is 81054781. The next prime is 81054821. The reversal of 81054820 is 2845018.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is not an unprimeable number, because it can be changed into a prime (81054821) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 786889 + ... + 786991.

It is an arithmetic number, because the mean of its divisors is an integer number (1535352).

Almost surely, 2^81054820 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 81054820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110545344).

81054820 is an abundant number, since it is smaller than the sum of its proper divisors (140035868).

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

81054820 is a wasteful number, since it uses less digits than its factorization.

81054820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210 (or 201 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 28.

The square root of 81054820 is about 9003.0450404294. The cubic root of 81054820 is about 432.7724591065.

Adding to 81054820 its reverse (2845018), we get a palindrome (83899838).

The spelling of 81054820 in words is "eighty-one million, fifty-four thousand, eight hundred twenty".