81349137 has 32 divisors (see below), whose sum is σ = 127100160. Its totient is φ = 51321600.

The previous prime is 81349133. The next prime is 81349139. The reversal of 81349137 is 73194318.

It is a happy number.

It is not a de Polignac number, because 81349137 - 2² = 81349133 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81349133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 62073 + ... + 63369.

It is an arithmetic number, because the mean of its divisors is an integer number (3971880).

Almost surely, 2^81349137 is an apocalyptic number.

It is an amenable number.

81349137 is a deficient number, since it is larger than the sum of its proper divisors (45751023).

81349137 is a wasteful number, since it uses less digits than its factorization.

81349137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1430 (or 1424 counting only the distinct ones).

The product of its digits is 18144, while the sum is 36.

The square root of 81349137 is about 9019.3756435798. The cubic root of 81349137 is about 433.2956376808.

It can be divided in two parts, 8134 and 9137, that added together give a palindrome (17271).

The spelling of 81349137 in words is "eighty-one million, three hundred forty-nine thousand, one hundred thirty-seven".