99943661 has 2 divisors, whose sum is σ = 99943662. Its totient is φ = 99943660.

The previous prime is 99943639. The next prime is 99943709. The reversal of 99943661 is 16634999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 70241161 + 29702500 = 8381^2 + 5450^2 .

It is a cyclic number.

It is not a de Polignac number, because 99943661 - 2¹⁴ = 99927277 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99943621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49971830 + 49971831.

It is an arithmetic number, because the mean of its divisors is an integer number (49971831).

Almost surely, 2^99943661 is an apocalyptic number.

It is an amenable number.

99943661 is a deficient number, since it is larger than the sum of its proper divisors (1).

99943661 is an equidigital number, since it uses as much as digits as its factorization.

99943661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 314928, while the sum is 47.

The square root of 99943661 is about 9997.1826531278. The cubic root of 99943661 is about 464.0716994953.

It can be divided in two parts, 99 and 943661, that multiplied together give a palindrome (93422439).

The spelling of 99943661 in words is "ninety-nine million, nine hundred forty-three thousand, six hundred sixty-one".