81228705043 has 4 divisors (see below), whose sum is σ = 81231284008. Its totient is φ = 81226126080.

The previous prime is 81228705037. The next prime is 81228705053. The reversal of 81228705043 is 34050782218.

It is a happy number.

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-81228705043 is a prime.

It is the 285007-th Hogben number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81228704987 and 81228705005.

It is not an unprimeable number, because it can be changed into a prime (81228705053) by changing a digit.

It is a nontrivial repunit in base 285006.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1241646 + ... + 1305427.

It is an arithmetic number, because the mean of its divisors is an integer number (20307821002).

Almost surely, 2^81228705043 is an apocalyptic number.

81228705043 is a deficient number, since it is larger than the sum of its proper divisors (2578965).

81228705043 is a wasteful number, since it uses less digits than its factorization.

81228705043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2578964.

The product of its (nonzero) digits is 107520, while the sum is 40.

The spelling of 81228705043 in words is "eighty-one billion, two hundred twenty-eight million, seven hundred five thousand, forty-three".