81650361 has 16 divisors (see below), whose sum is σ = 118036800. Its totient is φ = 49905600.

The previous prime is 81650357. The next prime is 81650389. The reversal of 81650361 is 16305618.

It is not a de Polignac number, because 81650361 - 2² = 81650357 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81650321) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1215 + ... + 12836.

It is an arithmetic number, because the mean of its divisors is an integer number (7377300).

Almost surely, 2^81650361 is an apocalyptic number.

It is an amenable number.

81650361 is a deficient number, since it is larger than the sum of its proper divisors (36386439).

81650361 is a wasteful number, since it uses less digits than its factorization.

81650361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14216.

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 81650361 is about 9036.0589307507. The cubic root of 81650361 is about 433.8297891293.

Adding to 81650361 its reverse (16305618), we get a palindrome (97955979).

The spelling of 81650361 in words is "eighty-one million, six hundred fifty thousand, three hundred sixty-one".