81782610 has 128 divisors (see below), whose sum is σ = 250145280. Its totient is φ = 16644096.

The previous prime is 81782609. The next prime is 81782611. The reversal of 81782610 is 1628718.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81782609) and next prime (81782611).

It is not an unprimeable number, because it can be changed into a prime (81782611) 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 63 ways as a sum of consecutive naturals, for example, 78654 + ... + 79686.

It is an arithmetic number, because the mean of its divisors is an integer number (1954260).

Almost surely, 2^81782610 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81782610, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (125072640).

81782610 is an abundant number, since it is smaller than the sum of its proper divisors (168362670).

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

81782610 is a wasteful number, since it uses less digits than its factorization.

81782610 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1092.

The product of its (nonzero) digits is 5376, while the sum is 33.

The square root of 81782610 is about 9043.3738173317. The cubic root of 81782610 is about 434.0638873295.

The spelling of 81782610 in words is "eighty-one million, seven hundred eighty-two thousand, six hundred ten".