81337688 has 8 divisors (see below), whose sum is σ = 152508180. Its totient is φ = 40668840.

The previous prime is 81337681. The next prime is 81337699. The reversal of 81337688 is 88673318.

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-3 number, since 3×81337688³ (a number of 25 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81337681) 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 as a sum of consecutive naturals, namely, 5083598 + ... + 5083613.

Almost surely, 2^81337688 is an apocalyptic number.

It is an amenable number.

81337688 is a deficient number, since it is larger than the sum of its proper divisors (71170492).

81337688 is a wasteful number, since it uses less digits than its factorization.

81337688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10167217 (or 10167213 counting only the distinct ones).

The product of its digits is 193536, while the sum is 44.

The square root of 81337688 is about 9018.7409320814. The cubic root of 81337688 is about 433.2753095222.

The spelling of 81337688 in words is "eighty-one million, three hundred thirty-seven thousand, six hundred eighty-eight".