81437138 has 8 divisors (see below), whose sum is σ = 122735280. Its totient is φ = 40525380.

The previous prime is 81437137. The next prime is 81437159. The reversal of 81437138 is 83173418.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 81437098 and 81437107.

It is not an unprimeable number, because it can be changed into a prime (81437131) 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 in 3 ways as a sum of consecutive naturals, for example, 96068 + ... + 96911.

It is an arithmetic number, because the mean of its divisors is an integer number (15341910).

Almost surely, 2^81437138 is an apocalyptic number.

81437138 is a deficient number, since it is larger than the sum of its proper divisors (41298142).

81437138 is a wasteful number, since it uses less digits than its factorization.

81437138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193192.

The product of its digits is 16128, while the sum is 35.

The square root of 81437138 is about 9024.2527668500. The cubic root of 81437138 is about 433.4518233501.

The spelling of 81437138 in words is "eighty-one million, four hundred thirty-seven thousand, one hundred thirty-eight".