99999623 has 2 divisors, whose sum is σ = 99999624. Its totient is φ = 99999622.

The previous prime is 99999617. The next prime is 99999643. The reversal of 99999623 is 32699999.

It is a weak prime.

It is an emirp because it is prime and its reverse (32699999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 99999623 - 2¹² = 99995527 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99999643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49999811 + 49999812.

It is an arithmetic number, because the mean of its divisors is an integer number (49999812).

Almost surely, 2^99999623 is an apocalyptic number.

99999623 is a deficient number, since it is larger than the sum of its proper divisors (1).

99999623 is an equidigital number, since it uses as much as digits as its factorization.

99999623 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2125764, while the sum is 56.

The square root of 99999623 is about 9999.9811499822. The cubic root of 99999623 is about 464.1583000675.

The spelling of 99999623 in words is "ninety-nine million, nine hundred ninety-nine thousand, six hundred twenty-three".