81072000 has 192 divisors, whose sum is σ = 291666960. Its totient is φ = 21580800.

The previous prime is 81071983. The next prime is 81072011. The reversal of 81072000 is 27018.

It is a tau number, because it is divible by the number of its divisors (192).

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 143719 + ... + 144281.

Almost surely, 2^81072000 is an apocalyptic number.

81072000 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 81072000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145833480).

81072000 is an abundant number, since it is smaller than the sum of its proper divisors (210594960).

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

81072000 is a wasteful number, since it uses less digits than its factorization.

81072000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 598 (or 573 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 18.

The square root of 81072000 is about 9003.9991115060. Note that the first 3 decimals coincide. The cubic root of 81072000 is about 432.8030330876.

Adding to 81072000 its reverse (27018), we get a palindrome (81099018).

The spelling of 81072000 in words is "eighty-one million, seventy-two thousand".