81264120 has 128 divisors (see below), whose sum is σ = 282009600. Its totient is φ = 18349056.

The previous prime is 81264101. The next prime is 81264133. The reversal of 81264120 is 2146218.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 74217 + ... + 75303.

It is an arithmetic number, because the mean of its divisors is an integer number (2203200).

Almost surely, 2^81264120 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 81264120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (141004800).

81264120 is an abundant number, since it is smaller than the sum of its proper divisors (200745480).

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

81264120 is a wasteful number, since it uses less digits than its factorization.

81264120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1197 (or 1193 counting only the distinct ones).

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

The square root of 81264120 is about 9014.6613913114. The cubic root of 81264120 is about 433.1446410555.

It can be divided in two parts, 8126 and 4120, that added together give a triangular number (12246 = T₁₅₆).

The spelling of 81264120 in words is "eighty-one million, two hundred sixty-four thousand, one hundred twenty".