81389064 has 32 divisors (see below), whose sum is σ = 215442720. Its totient is φ = 25533696.

The previous prime is 81389023. The next prime is 81389069. The reversal of 81389064 is 46098318.

It is not an unprimeable number, because it can be changed into a prime (81389069) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 99334 + ... + 100149.

It is an arithmetic number, because the mean of its divisors is an integer number (6732585).

Almost surely, 2^81389064 is an apocalyptic number.

It is an amenable number.

81389064 is an abundant number, since it is smaller than the sum of its proper divisors (134053656).

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

81389064 is a wasteful number, since it uses less digits than its factorization.

81389064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199509 (or 199505 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 39.

The square root of 81389064 is about 9021.5887736030. The cubic root of 81389064 is about 433.3665147504.

The spelling of 81389064 in words is "eighty-one million, three hundred eighty-nine thousand, sixty-four".