81609234 has 16 divisors (see below), whose sum is σ = 186535488. Its totient is φ = 23316912.

The previous prime is 81609223. The next prime is 81609271. The reversal of 81609234 is 43290618.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 81609195 and 81609204.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 971497 + ... + 971580.

It is an arithmetic number, because the mean of its divisors is an integer number (11658468).

Almost surely, 2^81609234 is an apocalyptic number.

81609234 is an abundant number, since it is smaller than the sum of its proper divisors (104926254).

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

81609234 is a wasteful number, since it uses less digits than its factorization.

81609234 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1943089.

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 81609234 is about 9033.7829285411. The cubic root of 81609234 is about 433.7569373826.

The spelling of 81609234 in words is "eighty-one million, six hundred nine thousand, two hundred thirty-four".