81874 has 16 divisors (see below), whose sum is σ = 137088. Its totient is φ = 36432.

The previous prime is 81869. The next prime is 81883. The reversal of 81874 is 47818.

81874 = T₁₂ + T₁₃ + ... + T₇₈.

It is an Ulam number.

It is an alternating number because its digits alternate between even and odd.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1189 + ... + 1255.

It is an arithmetic number, because the mean of its divisors is an integer number (8568).

2⁸¹⁸⁷⁴ is an apocalyptic number.

81874 is a deficient number, since it is larger than the sum of its proper divisors (55214).

81874 is a wasteful number, since it uses less digits than its factorization.

81874 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129.

The product of its digits is 1792, while the sum is 28.

The square root of 81874 is about 286.1363311430. The cubic root of 81874 is about 43.4225512282.

The spelling of 81874 in words is "eighty-one thousand, eight hundred seventy-four".