81510912 has 270 divisors, whose sum is σ = 288814383. Its totient is φ = 22063104.

The previous prime is 81510899. The next prime is 81510941. The reversal of 81510912 is 21901518.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in only one way, i.e., 40755456 + 40755456 = 6384^2 + 6384^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=6384.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 4290039 + ... + 4290057.

Almost surely, 2^81510912 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 81510912

81510912 is an abundant number, since it is smaller than the sum of its proper divisors (207303471).

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

81510912 is a wasteful number, since it uses less digits than its factorization.

81510912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76 (or 31 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 27.

The square root of 81510912 is about 9028.3393821898. The cubic root of 81510912 is about 433.5826720199.

The spelling of 81510912 in words is "eighty-one million, five hundred ten thousand, nine hundred twelve".