81232985 has 4 divisors (see below), whose sum is σ = 97479588. Its totient is φ = 64986384.

The previous prime is 81232979. The next prime is 81232997. The reversal of 81232985 is 58923218.

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

It can be written as a sum of positive squares in 2 ways, for example, as 47720464 + 33512521 = 6908^2 + 5789^2 .

It is a cyclic number.

It is not a de Polignac number, because 81232985 - 2¹⁴ = 81216601 is a prime.

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

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8123294 + ... + 8123303.

It is an arithmetic number, because the mean of its divisors is an integer number (24369897).

Almost surely, 2^81232985 is an apocalyptic number.

It is an amenable number.

81232985 is a deficient number, since it is larger than the sum of its proper divisors (16246603).

81232985 is a wasteful number, since it uses less digits than its factorization.

81232985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16246602.

The product of its digits is 34560, while the sum is 38.

The square root of 81232985 is about 9012.9343168582. The cubic root of 81232985 is about 433.0893165938.

The spelling of 81232985 in words is "eighty-one million, two hundred thirty-two thousand, nine hundred eighty-five".