81450688 has 56 divisors (see below), whose sum is σ = 177905664. Its totient is φ = 36691200.

The previous prime is 81450683. The next prime is 81450697. The reversal of 81450688 is 88605418.

81450688 = 737² + 738² + ... + 863².

It is a self number, because there is not a number n which added to its sum of digits gives 81450688.

It is not an unprimeable number, because it can be changed into a prime (81450683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88953 + ... + 89863.

Almost surely, 2^81450688 is an apocalyptic number.

81450688 is a gapful number since it is divisible by the number (88) 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 81450688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88952832).

81450688 is an abundant number, since it is smaller than the sum of its proper divisors (96454976).

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

81450688 is a wasteful number, since it uses less digits than its factorization.

81450688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1061 (or 1051 counting only the distinct ones).

The product of its (nonzero) digits is 61440, while the sum is 40.

The square root of 81450688 is about 9025.0034903040. The cubic root of 81450688 is about 433.4758621226.

The spelling of 81450688 in words is "eighty-one million, four hundred fifty thousand, six hundred eighty-eight".