81967723 has 2 divisors, whose sum is σ = 81967724. Its totient is φ = 81967722.

The previous prime is 81967649. The next prime is 81967747. The reversal of 81967723 is 32776918.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81967723 - 2⁹ = 81967211 is a prime.

It is a super-2 number, since 2×81967723² = 13437415227609458, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81967723.

It is not a weakly prime, because it can be changed into another prime (81967763) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40983861 + 40983862.

It is an arithmetic number, because the mean of its divisors is an integer number (40983862).

Almost surely, 2^81967723 is an apocalyptic number.

81967723 is a deficient number, since it is larger than the sum of its proper divisors (1).

81967723 is an equidigital number, since it uses as much as digits as its factorization.

81967723 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 127008, while the sum is 43.

The square root of 81967723 is about 9053.6027635412. The cubic root of 81967723 is about 434.3911383201.

The spelling of 81967723 in words is "eighty-one million, nine hundred sixty-seven thousand, seven hundred twenty-three".