81624223 has 2 divisors, whose sum is σ = 81624224. Its totient is φ = 81624222.

The previous prime is 81624211. The next prime is 81624251. The reversal of 81624223 is 32242618.

It is an a-pointer prime, because the next prime (81624251) can be obtained adding 81624223 to its sum of digits (28).

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81624223 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81624191 and 81624200.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81624203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40812111 + 40812112.

It is an arithmetic number, because the mean of its divisors is an integer number (40812112).

Almost surely, 2^81624223 is an apocalyptic number.

81624223 is a deficient number, since it is larger than the sum of its proper divisors (1).

81624223 is an equidigital number, since it uses as much as digits as its factorization.

81624223 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4608, while the sum is 28.

The square root of 81624223 is about 9034.6124986078. The cubic root of 81624223 is about 433.7834915049.

The spelling of 81624223 in words is "eighty-one million, six hundred twenty-four thousand, two hundred twenty-three".