81106641 has 24 divisors (see below), whose sum is σ = 146063424. Its totient is φ = 42132960.

The previous prime is 81106621. The next prime is 81106657. The reversal of 81106641 is 14660118.

81106641 is a `hidden beast` number, since 8 + 1 + 10 + 6 + 641 = 666.

It is not a de Polignac number, because 81106641 - 2¹¹ = 81104593 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81106621) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 57826 + ... + 59211.

It is an arithmetic number, because the mean of its divisors is an integer number (6085976).

Almost surely, 2^81106641 is an apocalyptic number.

It is an amenable number.

81106641 is a deficient number, since it is larger than the sum of its proper divisors (64956783).

81106641 is a wasteful number, since it uses less digits than its factorization.

81106641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117061 (or 117058 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 81106641 is about 9005.9225512992. The cubic root of 81106641 is about 432.8646679923.

Adding to 81106641 its reverse (14660118), we get a palindrome (95766759).

The spelling of 81106641 in words is "eighty-one million, one hundred six thousand, six hundred forty-one".