81873064 has 96 divisors (see below), whose sum is σ = 195531840. Its totient is φ = 31449600.

The previous prime is 81873059. The next prime is 81873067. The reversal of 81873064 is 46037818.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (81873067) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 387919 + ... + 388129.

It is an arithmetic number, because the mean of its divisors is an integer number (2036790).

Almost surely, 2^81873064 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 81873064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (97765920).

81873064 is an abundant number, since it is smaller than the sum of its proper divisors (113658776).

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

81873064 is a wasteful number, since it uses less digits than its factorization.

81873064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291 (or 274 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 37.

The square root of 81873064 is about 9048.3735555071. The cubic root of 81873064 is about 434.2238575582.

The spelling of 81873064 in words is "eighty-one million, eight hundred seventy-three thousand, sixty-four".