81283020 has 96 divisors (see below), whose sum is σ = 280132608. Its totient is φ = 17148672.

The previous prime is 81283019. The next prime is 81283039. The reversal of 81283020 is 2038218.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1984 + ... + 12903.

It is an arithmetic number, because the mean of its divisors is an integer number (2918048).

Almost surely, 2^81283020 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 81283020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (140066304).

81283020 is an abundant number, since it is smaller than the sum of its proper divisors (198849588).

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

81283020 is a wasteful number, since it uses less digits than its factorization.

81283020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14919 (or 14917 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 81283020 is about 9015.7096226531. The cubic root of 81283020 is about 433.1782179860.

The spelling of 81283020 in words is "eighty-one million, two hundred eighty-three thousand, twenty".