81609061 has 8 divisors (see below), whose sum is σ = 88248960. Its totient is φ = 75173568.

The previous prime is 81609001. The next prime is 81609067. The reversal of 81609061 is 16090618.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 81609061 - 2¹⁵ = 81576293 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81609067) 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, 50271 + ... + 51868.

It is an arithmetic number, because the mean of its divisors is an integer number (11031120).

Almost surely, 2^81609061 is an apocalyptic number.

It is an amenable number.

81609061 is a deficient number, since it is larger than the sum of its proper divisors (6639899).

81609061 is a wasteful number, since it uses less digits than its factorization.

81609061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102203.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 81609061 is about 9033.7733533668. The cubic root of 81609061 is about 433.7566308814.

Adding to 81609061 its reverse (16090618), we get a palindrome (97699679).

The spelling of 81609061 in words is "eighty-one million, six hundred nine thousand, sixty-one".