81210284 has 12 divisors (see below), whose sum is σ = 142246608. Its totient is φ = 40568400.

The previous prime is 81210281. The next prime is 81210289. The reversal of 81210284 is 48201218.

It is a super-2 number, since 2×81210284² = 13190220454721312, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81210281) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3872 + ... + 13319.

It is an arithmetic number, because the mean of its divisors is an integer number (11853884).

Almost surely, 2^81210284 is an apocalyptic number.

It is an amenable number.

81210284 is a deficient number, since it is larger than the sum of its proper divisors (61036324).

81210284 is a wasteful number, since it uses less digits than its factorization.

81210284 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18376 (or 18374 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 26.

The square root of 81210284 is about 9011.6748720757. The cubic root of 81210284 is about 433.0489697793.

The spelling of 81210284 in words is "eighty-one million, two hundred ten thousand, two hundred eighty-four".