81284260 has 12 divisors (see below), whose sum is σ = 170696988. Its totient is φ = 32513696.

The previous prime is 81284257. The next prime is 81284309. The reversal of 81284260 is 6248218.

It can be written as a sum of positive squares in 2 ways, for example, as 8386816 + 72897444 = 2896^2 + 8538^2 .

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 3 ways as a sum of consecutive naturals, for example, 2032087 + ... + 2032126.

It is an arithmetic number, because the mean of its divisors is an integer number (14224749).

Almost surely, 2^81284260 is an apocalyptic number.

It is an amenable number.

81284260 is an abundant number, since it is smaller than the sum of its proper divisors (89412728).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81284260 is a wasteful number, since it uses less digits than its factorization.

81284260 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4064222 (or 4064220 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 31.

The square root of 81284260 is about 9015.7783912428. The cubic root of 81284260 is about 433.1804207350.

The spelling of 81284260 in words is "eighty-one million, two hundred eighty-four thousand, two hundred sixty".