15993049661 has 2 divisors, whose sum is σ = 15993049662. Its totient is φ = 15993049660.

The previous prime is 15993049627. The next prime is 15993049663. The reversal of 15993049661 is 16694039951.

It is a happy number.

15993049661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14964628900 + 1028420761 = 122330^2 + 32069^2 .

It is an emirp because it is prime and its reverse (16694039951) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15993049661 is a prime.

It is a Sophie Germain prime.

Together with 15993049663, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15993049663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7996524830 + 7996524831.

It is an arithmetic number, because the mean of its divisors is an integer number (7996524831).

Almost surely, 2^15993049661 is an apocalyptic number.

It is an amenable number.

15993049661 is a deficient number, since it is larger than the sum of its proper divisors (1).

15993049661 is an equidigital number, since it uses as much as digits as its factorization.

15993049661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1574640, while the sum is 53.

The spelling of 15993049661 in words is "fifteen billion, nine hundred ninety-three million, forty-nine thousand, six hundred sixty-one".