81948233 has 4 divisors (see below), whose sum is σ = 81976980. Its totient is φ = 81919488.

The previous prime is 81948199. The next prime is 81948247. The reversal of 81948233 is 33284918.

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

It can be written as a sum of positive squares in 2 ways, for example, as 65723449 + 16224784 = 8107^2 + 4028^2 .

It is a cyclic number.

It is not a de Polignac number, because 81948233 - 2¹⁸ = 81686089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81948133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9560 + ... + 15977.

It is an arithmetic number, because the mean of its divisors is an integer number (20494245).

Almost surely, 2^81948233 is an apocalyptic number.

It is an amenable number.

81948233 is a deficient number, since it is larger than the sum of its proper divisors (28747).

81948233 is a wasteful number, since it uses less digits than its factorization.

81948233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28746.

The product of its digits is 41472, while the sum is 38.

The square root of 81948233 is about 9052.5263324665. The cubic root of 81948233 is about 434.3567062530.

The spelling of 81948233 in words is "eighty-one million, nine hundred forty-eight thousand, two hundred thirty-three".