81876985 has 16 divisors (see below), whose sum is σ = 104385600. Its totient is φ = 61477056.

The previous prime is 81876931. The next prime is 81876989. The reversal of 81876985 is 58967818.

It is a cyclic number.

It is not a de Polignac number, because 81876985 - 2¹⁹ = 81352697 is a prime.

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

It is not an unprimeable number, because it can be changed into a prime (81876989) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6402 + ... + 14308.

It is an arithmetic number, because the mean of its divisors is an integer number (6524100).

Almost surely, 2^81876985 is an apocalyptic number.

It is an amenable number.

81876985 is a deficient number, since it is larger than the sum of its proper divisors (22508615).

81876985 is a wasteful number, since it uses less digits than its factorization.

81876985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8040.

The product of its digits is 967680, while the sum is 52.

The square root of 81876985 is about 9048.5902216865. The cubic root of 81876985 is about 434.2307892827.

The spelling of 81876985 in words is "eighty-one million, eight hundred seventy-six thousand, nine hundred eighty-five".