81120861 has 12 divisors (see below), whose sum is σ = 123341920. Its totient is φ = 51234120.

The previous prime is 81120847. The next prime is 81120863. The reversal of 81120861 is 16802118.

It is not a de Polignac number, because 81120861 - 2⁵ = 81120829 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81120863) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 237025 + ... + 237366.

Almost surely, 2^81120861 is an apocalyptic number.

It is an amenable number.

81120861 is a deficient number, since it is larger than the sum of its proper divisors (42221059).

81120861 is a wasteful number, since it uses less digits than its factorization.

81120861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 474416 (or 474413 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 27.

The square root of 81120861 is about 9006.7119971719. The cubic root of 81120861 is about 432.8899638078.

Adding to 81120861 its reverse (16802118), we get a palindrome (97922979).

The spelling of 81120861 in words is "eighty-one million, one hundred twenty thousand, eight hundred sixty-one".