81003872 has 12 divisors (see below), whose sum is σ = 159476436. Its totient is φ = 40501920.

The previous prime is 81003869. The next prime is 81003883. The reversal of 81003872 is 27830018.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1265654 + ... + 1265717.

It is an arithmetic number, because the mean of its divisors is an integer number (13289703).

Almost surely, 2^81003872 is an apocalyptic number.

It is an amenable number.

81003872 is a deficient number, since it is larger than the sum of its proper divisors (78472564).

81003872 is a wasteful number, since it uses less digits than its factorization.

81003872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2531381 (or 2531373 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 81003872 is about 9000.2151085405. The cubic root of 81003872 is about 432.6817652914.

The spelling of 81003872 in words is "eighty-one million, three thousand, eight hundred seventy-two".