81306270 has 24 divisors (see below), whose sum is σ = 211396536. Its totient is φ = 21681648.

The previous prime is 81306259. The next prime is 81306271. The reversal of 81306270 is 7260318.

81306270 is a `hidden beast` number, since 8 + 1 + 30 + 627 + 0 = 666.

It is a super-2 number, since 2×81306270² = 13221419082625800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81306271) 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 11 ways as a sum of consecutive naturals, for example, 451612 + ... + 451791.

It is an arithmetic number, because the mean of its divisors is an integer number (8808189).

Almost surely, 2^81306270 is an apocalyptic number.

81306270 is an abundant number, since it is smaller than the sum of its proper divisors (130090266).

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

81306270 is a wasteful number, since it uses less digits than its factorization.

81306270 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 903416 (or 903413 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 81306270 is about 9016.9989464345. The cubic root of 81306270 is about 433.2195158014.

Adding to 81306270 its reverse (7260318), we get a palindrome (88566588).

It can be divided in two parts, 8130 and 6270, that added together give a square (14400 = 120²).

The spelling of 81306270 in words is "eighty-one million, three hundred six thousand, two hundred seventy".