81600012 has 72 divisors (see below), whose sum is σ = 224244384. Its totient is φ = 24869376.

The previous prime is 81599993. The next prime is 81600023. The reversal of 81600012 is 21000618.

It is a Harshad number since it is a multiple of its sum of digits (18).

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 23 ways as a sum of consecutive naturals, for example, 52113 + ... + 53655.

Almost surely, 2^81600012 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 81600012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112122192).

81600012 is an abundant number, since it is smaller than the sum of its proper divisors (142644372).

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

81600012 is a wasteful number, since it uses less digits than its factorization.

81600012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1679 (or 1674 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 81600012 is about 9033.2724967201. The cubic root of 81600012 is about 433.7405983118.

The spelling of 81600012 in words is "eighty-one million, six hundred thousand, twelve".