81106747 has 4 divisors (see below), whose sum is σ = 81150640. Its totient is φ = 81062856.

The previous prime is 81106741. The next prime is 81106771. The reversal of 81106747 is 74760118.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81106747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81106741) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19047 + ... + 22912.

It is an arithmetic number, because the mean of its divisors is an integer number (20287660).

Almost surely, 2^81106747 is an apocalyptic number.

81106747 is a deficient number, since it is larger than the sum of its proper divisors (43893).

81106747 is a wasteful number, since it uses less digits than its factorization.

81106747 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43892.

The product of its (nonzero) digits is 9408, while the sum is 34.

The square root of 81106747 is about 9005.9284363135. The cubic root of 81106747 is about 432.8648565656.

The spelling of 81106747 in words is "eighty-one million, one hundred six thousand, seven hundred forty-seven".