81985606 has 8 divisors (see below), whose sum is σ = 125838504. Its totient is φ = 40039440.

The previous prime is 81985583. The next prime is 81985619. The reversal of 81985606 is 60658918.

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

It is a Harshad number since it is a multiple of its sum of digits (43).

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, 476575 + ... + 476746.

It is an arithmetic number, because the mean of its divisors is an integer number (15729813).

Almost surely, 2^81985606 is an apocalyptic number.

81985606 is a gapful number since it is divisible by the number (86) formed by its first and last digit.

81985606 is a deficient number, since it is larger than the sum of its proper divisors (43852898).

81985606 is a wasteful number, since it uses less digits than its factorization.

81985606 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 953366.

The product of its (nonzero) digits is 103680, while the sum is 43.

The square root of 81985606 is about 9054.5903275631. The cubic root of 81985606 is about 434.4227265745.

The spelling of 81985606 in words is "eighty-one million, nine hundred eighty-five thousand, six hundred six".