81530064 has 400 divisors, whose sum is σ = 316884480. Its totient is φ = 19595520.

The previous prime is 81530051. The next prime is 81530087. The reversal of 81530064 is 46003518.

It is a Harshad number since it is a multiple of its sum of digits (27).

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 79 ways as a sum of consecutive naturals, for example, 1896027 + ... + 1896069.

Almost surely, 2^81530064 is an apocalyptic number.

81530064 is a gapful number since it is divisible by the number (84) 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 81530064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (158442240).

81530064 is an abundant number, since it is smaller than the sum of its proper divisors (235354416).

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

81530064 is a wasteful number, since it uses less digits than its factorization.

81530064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100 (or 85 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 81530064 is about 9029.3999800651. The cubic root of 81530064 is about 433.6166279032.

The spelling of 81530064 in words is "eighty-one million, five hundred thirty thousand, sixty-four".