81839470 has 8 divisors (see below), whose sum is σ = 147311064. Its totient is φ = 32735784.

The previous prime is 81839467. The next prime is 81839477. The reversal of 81839470 is 7493818.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81839477) 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, 4091964 + ... + 4091983.

It is an arithmetic number, because the mean of its divisors is an integer number (18413883).

Almost surely, 2^81839470 is an apocalyptic number.

81839470 is a deficient number, since it is larger than the sum of its proper divisors (65471594).

81839470 is a wasteful number, since it uses less digits than its factorization.

81839470 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8183954.

The product of its (nonzero) digits is 48384, while the sum is 40.

The square root of 81839470 is about 9046.5170093246. The cubic root of 81839470 is about 434.1644594641.

The spelling of 81839470 in words is "eighty-one million, eight hundred thirty-nine thousand, four hundred seventy".