81946223 has 4 divisors (see below), whose sum is σ = 83068848. Its totient is φ = 80823600.

The previous prime is 81946219. The next prime is 81946253. The reversal of 81946223 is 32264918.

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

It is a cyclic number.

It is not a de Polignac number, because 81946223 - 2² = 81946219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81946253) 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, 561203 + ... + 561348.

It is an arithmetic number, because the mean of its divisors is an integer number (20767212).

Almost surely, 2^81946223 is an apocalyptic number.

81946223 is a deficient number, since it is larger than the sum of its proper divisors (1122625).

81946223 is a wasteful number, since it uses less digits than its factorization.

81946223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1122624.

The product of its digits is 20736, while the sum is 35.

The square root of 81946223 is about 9052.4153130532. The cubic root of 81946223 is about 434.3531549699.

The spelling of 81946223 in words is "eighty-one million, nine hundred forty-six thousand, two hundred twenty-three".