81281846 has 4 divisors (see below), whose sum is σ = 121922772. Its totient is φ = 40640922.

The previous prime is 81281833. The next prime is 81281869. The reversal of 81281846 is 64818218.

It is a semiprime because it is the product of two primes.

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, 20320460 + ... + 20320463.

It is an arithmetic number, because the mean of its divisors is an integer number (30480693).

Almost surely, 2^81281846 is an apocalyptic number.

81281846 is a deficient number, since it is larger than the sum of its proper divisors (40640926).

81281846 is a wasteful number, since it uses less digits than its factorization.

81281846 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40640925.

The product of its digits is 24576, while the sum is 38.

The square root of 81281846 is about 9015.6445138437. The cubic root of 81281846 is about 433.1761324595.

It can be divided in two parts, 812818 and 46, that multiplied together give a triangular number (37389628 = T₈₆₄₇).

The spelling of 81281846 in words is "eighty-one million, two hundred eighty-one thousand, eight hundred forty-six".