81936064 has 28 divisors (see below), whose sum is σ = 185820304. Its totient is φ = 35115264.

The previous prime is 81936031. The next prime is 81936067. The reversal of 81936064 is 46063918.

It is a tau number, because it is divible by the number of its divisors (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81936067) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 90999 + ... + 91894.

Almost surely, 2^81936064 is an apocalyptic number.

It is an amenable number.

81936064 is an abundant number, since it is smaller than the sum of its proper divisors (103884240).

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

81936064 is a wasteful number, since it uses less digits than its factorization.

81936064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 182912 (or 182902 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 37.

The square root of 81936064 is about 9051.8541746981. The cubic root of 81936064 is about 434.3352050840.

The spelling of 81936064 in words is "eighty-one million, nine hundred thirty-six thousand, sixty-four".