81226538 has 4 divisors (see below), whose sum is σ = 121839810. Its totient is φ = 40613268.

The previous prime is 81226531. The next prime is 81226543. The reversal of 81226538 is 83562218.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83562218 = 2 ⋅41781109.

It can be written as a sum of positive squares in only one way, i.e., 81126049 + 100489 = 9007^2 + 317^2 .

It is a junction number, because it is equal to n+sod(n) for n = 81226498 and 81226507.

It is not an unprimeable number, because it can be changed into a prime (81226531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20306633 + ... + 20306636.

Almost surely, 2^81226538 is an apocalyptic number.

81226538 is a deficient number, since it is larger than the sum of its proper divisors (40613272).

81226538 is a wasteful number, since it uses less digits than its factorization.

81226538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40613271.

The product of its digits is 23040, while the sum is 35.

The square root of 81226538 is about 9012.5766570942. The cubic root of 81226538 is about 433.0778590121.

The spelling of 81226538 in words is "eighty-one million, two hundred twenty-six thousand, five hundred thirty-eight".