81986426 has 8 divisors (see below), whose sum is σ = 124815360. Its totient is φ = 40381308.

The previous prime is 81986419. The next prime is 81986431. The reversal of 81986426 is 62468918.

It is a happy number.

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

It is an unprimeable number.

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, 305786 + ... + 306053.

It is an arithmetic number, because the mean of its divisors is an integer number (15601920).

Almost surely, 2^81986426 is an apocalyptic number.

81986426 is a deficient number, since it is larger than the sum of its proper divisors (42828934).

81986426 is a wasteful number, since it uses less digits than its factorization.

81986426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 611908.

The product of its digits is 165888, while the sum is 44.

The square root of 81986426 is about 9054.6356083500. The cubic root of 81986426 is about 434.4241748996.

The spelling of 81986426 in words is "eighty-one million, nine hundred eighty-six thousand, four hundred twenty-six".