99943639 has 2 divisors, whose sum is σ = 99943640. Its totient is φ = 99943638.

The previous prime is 99943621. The next prime is 99943661. The reversal of 99943639 is 93634999.

It is a weak prime.

It is an emirp because it is prime and its reverse (93634999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 99943639 - 2⁵ = 99943607 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99943619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49971819 + 49971820.

It is an arithmetic number, because the mean of its divisors is an integer number (49971820).

Almost surely, 2^99943639 is an apocalyptic number.

99943639 is a deficient number, since it is larger than the sum of its proper divisors (1).

99943639 is an equidigital number, since it uses as much as digits as its factorization.

99943639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1417176, while the sum is 52.

The square root of 99943639 is about 9997.1815528178. The cubic root of 99943639 is about 464.0716654442.

The spelling of 99943639 in words is "ninety-nine million, nine hundred forty-three thousand, six hundred thirty-nine".