81540838 has 8 divisors (see below), whose sum is σ = 122364000. Its totient is φ = 40752840.

The previous prime is 81540803. The next prime is 81540853. The reversal of 81540838 is 83804518.

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

It is a junction number, because it is equal to n+sod(n) for n = 81540797 and 81540806.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1918 + ... + 12913.

It is an arithmetic number, because the mean of its divisors is an integer number (15295500).

Almost surely, 2^81540838 is an apocalyptic number.

81540838 is a deficient number, since it is larger than the sum of its proper divisors (40823162).

81540838 is a wasteful number, since it uses less digits than its factorization.

81540838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17582.

The product of its (nonzero) digits is 30720, while the sum is 37.

The square root of 81540838 is about 9029.9965669982. The cubic root of 81540838 is about 433.6357275234.

The spelling of 81540838 in words is "eighty-one million, five hundred forty thousand, eight hundred thirty-eight".