81609411 has 8 divisors (see below), whose sum is σ = 117182800. Its totient is φ = 50221152.

The previous prime is 81609397. The next prime is 81609413. The reversal of 81609411 is 11490618.

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

It is not a de Polignac number, because 81609411 - 2⁵ = 81609379 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81609413) 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 7 ways as a sum of consecutive naturals, for example, 1046236 + ... + 1046313.

It is an arithmetic number, because the mean of its divisors is an integer number (14647850).

Almost surely, 2^81609411 is an apocalyptic number.

81609411 is a deficient number, since it is larger than the sum of its proper divisors (35573389).

81609411 is a wasteful number, since it uses less digits than its factorization.

81609411 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2092565.

The product of its (nonzero) digits is 1728, while the sum is 30.

The square root of 81609411 is about 9033.7927250961. The cubic root of 81609411 is about 433.7572509702.

It can be divided in two parts, 8160 and 9411, that added together give a palindrome (17571).

The spelling of 81609411 in words is "eighty-one million, six hundred nine thousand, four hundred eleven".