81270000 has 400 divisors, whose sum is σ = 340890880. Its totient is φ = 18144000.

The previous prime is 81269999. The next prime is 81270001. The reversal of 81270000 is 7218.

It is an interprime number because it is at equal distance from previous prime (81269999) and next prime (81270001).

It is a tau number, because it is divible by the number of its divisors (400).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81270001) by changing a digit.

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 79 ways as a sum of consecutive naturals, for example, 1889979 + ... + 1890021.

Almost surely, 2^81270000 is an apocalyptic number.

81270000 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 81270000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (170445440).

81270000 is an abundant number, since it is smaller than the sum of its proper divisors (259620880).

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

81270000 is a wasteful number, since it uses less digits than its factorization.

81270000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87 (or 60 counting only the distinct ones).

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

The square root of 81270000 is about 9014.9875207900. The cubic root of 81270000 is about 433.1550877695.

Adding to 81270000 its reverse (7218), we get a palindrome (81277218).

The spelling of 81270000 in words is "eighty-one million, two hundred seventy thousand".