81276864 has 112 divisors (see below), whose sum is σ = 234196128. Its totient is φ = 24772608.

The previous prime is 81276863. The next prime is 81276869. The reversal of 81276864 is 46867218.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81276863) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 120432 + ... + 121104.

Almost surely, 2^81276864 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 81276864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117098064).

81276864 is an abundant number, since it is smaller than the sum of its proper divisors (152919264).

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

81276864 is a wasteful number, since it uses less digits than its factorization.

81276864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 742 (or 732 counting only the distinct ones).

The product of its digits is 129024, while the sum is 42.

The square root of 81276864 is about 9015.3682121142. The cubic root of 81276864 is about 433.1672820717.

The spelling of 81276864 in words is "eighty-one million, two hundred seventy-six thousand, eight hundred sixty-four".