81284310 has 80 divisors (see below), whose sum is σ = 231460416. Its totient is φ = 20397312.

The previous prime is 81284309. The next prime is 81284311. The reversal of 81284310 is 1348218.

It is an interprime number because it is at equal distance from previous prime (81284309) and next prime (81284311).

It is a super-2 number, since 2×81284310² = 13214278104352200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81284311) by changing a digit.

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 39 ways as a sum of consecutive naturals, for example, 10819 + ... + 16721.

Almost surely, 2^81284310 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81284310, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (115730208).

81284310 is an abundant number, since it is smaller than the sum of its proper divisors (150176106).

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

81284310 is a wasteful number, since it uses less digits than its factorization.

81284310 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5939 (or 5930 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 81284310 is about 9015.7811641588. The cubic root of 81284310 is about 433.1805095550.

The spelling of 81284310 in words is "eighty-one million, two hundred eighty-four thousand, three hundred ten".