81736767 has 24 divisors (see below), whose sum is σ = 137148960. Its totient is φ = 45938880.

The previous prime is 81736763. The next prime is 81736769. The reversal of 81736767 is 76763718.

It is a happy number.

It is not a de Polignac number, because 81736767 - 2² = 81736763 is a prime.

It is a super-2 number, since 2×81736767² = 13361798159224578, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81736763) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6792 + ... + 14477.

It is an arithmetic number, because the mean of its divisors is an integer number (5714540).

Almost surely, 2^81736767 is an apocalyptic number.

81736767 is a deficient number, since it is larger than the sum of its proper divisors (55412193).

81736767 is a wasteful number, since it uses less digits than its factorization.

81736767 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21343 (or 21340 counting only the distinct ones).

The product of its digits is 296352, while the sum is 45.

The square root of 81736767 is about 9040.8388438242. The cubic root of 81736767 is about 433.9827677614.

The spelling of 81736767 in words is "eighty-one million, seven hundred thirty-six thousand, seven hundred sixty-seven".