81443870 has 8 divisors (see below), whose sum is σ = 146598984. Its totient is φ = 32577544.

The previous prime is 81443867. The next prime is 81443909. The reversal of 81443870 is 7834418.

It is a happy number.

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

It is a self number, because there is not a number n which added to its sum of digits gives 81443870.

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, 4072184 + ... + 4072203.

It is an arithmetic number, because the mean of its divisors is an integer number (18324873).

Almost surely, 2^81443870 is an apocalyptic number.

81443870 is a deficient number, since it is larger than the sum of its proper divisors (65155114).

81443870 is a wasteful number, since it uses less digits than its factorization.

81443870 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8144394.

The product of its (nonzero) digits is 21504, while the sum is 35.

The square root of 81443870 is about 9024.6257540133. The cubic root of 81443870 is about 433.4637667842.

The spelling of 81443870 in words is "eighty-one million, four hundred forty-three thousand, eight hundred seventy".