81183623 has 2 divisors, whose sum is σ = 81183624. Its totient is φ = 81183622.

The previous prime is 81183611. The next prime is 81183667. The reversal of 81183623 is 32638118.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81183623 - 2⁶ = 81183559 is a prime.

It is a super-2 number, since 2×81183623² = 13181561286812258, 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 81183623.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81180623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40591811 + 40591812.

It is an arithmetic number, because the mean of its divisors is an integer number (40591812).

Almost surely, 2^81183623 is an apocalyptic number.

81183623 is a deficient number, since it is larger than the sum of its proper divisors (1).

81183623 is an equidigital number, since it uses as much as digits as its factorization.

81183623 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6912, while the sum is 32.

The square root of 81183623 is about 9010.1955028734. The cubic root of 81183623 is about 433.0015751978.

The spelling of 81183623 in words is "eighty-one million, one hundred eighty-three thousand, six hundred twenty-three".