81782211 has 8 divisors (see below), whose sum is σ = 124620544. Its totient is φ = 46732680.

The previous prime is 81782203. The next prime is 81782219. The reversal of 81782211 is 11228718.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81782203) and next prime (81782219).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81782211 - 2³ = 81782203 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81782219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1947175 + ... + 1947216.

It is an arithmetic number, because the mean of its divisors is an integer number (15577568).

Almost surely, 2^81782211 is an apocalyptic number.

81782211 is a deficient number, since it is larger than the sum of its proper divisors (42838333).

81782211 is a wasteful number, since it uses less digits than its factorization.

81782211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3894401.

The product of its digits is 1792, while the sum is 30.

The square root of 81782211 is about 9043.3517569538. The cubic root of 81782211 is about 434.0631814265.

It can be divided in two parts, 817 and 82211, that added together give a triangular number (83028 = T₄₀₇).

The spelling of 81782211 in words is "eighty-one million, seven hundred eighty-two thousand, two hundred eleven".