99913661 has 2 divisors, whose sum is σ = 99913662. Its totient is φ = 99913660.

The previous prime is 99913643. The next prime is 99913673. The reversal of 99913661 is 16631999.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 83356900 + 16556761 = 9130^2 + 4069^2 .

It is an emirp because it is prime and its reverse (16631999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 99913661 - 2¹⁴ = 99897277 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 (99913601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49956830 + 49956831.

It is an arithmetic number, because the mean of its divisors is an integer number (49956831).

Almost surely, 2^99913661 is an apocalyptic number.

It is an amenable number.

99913661 is a deficient number, since it is larger than the sum of its proper divisors (1).

99913661 is an equidigital number, since it uses as much as digits as its factorization.

99913661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 78732, while the sum is 44.

The square root of 99913661 is about 9995.6821177947. The cubic root of 99913661 is about 464.0252615185.

The spelling of 99913661 in words is "ninety-nine million, nine hundred thirteen thousand, six hundred sixty-one".