81144470 has 32 divisors (see below), whose sum is σ = 162051840. Its totient is φ = 29004640.

The previous prime is 81144467. The next prime is 81144473. The reversal of 81144470 is 7444118.

It is an interprime number because it is at equal distance from previous prime (81144467) and next prime (81144473).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81144473) 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 15 ways as a sum of consecutive naturals, for example, 239 + ... + 12741.

It is an arithmetic number, because the mean of its divisors is an integer number (5064120).

Almost surely, 2^81144470 is an apocalyptic number.

81144470 is a deficient number, since it is larger than the sum of its proper divisors (80907370).

81144470 is a wasteful number, since it uses less digits than its factorization.

81144470 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12580.

The product of its (nonzero) digits is 3584, while the sum is 29.

The square root of 81144470 is about 9008.0225354958. The cubic root of 81144470 is about 432.9319550939.

Adding to 81144470 its reverse (7444118), we get a palindrome (88588588).

The spelling of 81144470 in words is "eighty-one million, one hundred forty-four thousand, four hundred seventy".