15649 has 2 divisors, whose sum is σ = 15650. Its totient is φ = 15648.

The previous prime is 15647. The next prime is 15661. The reversal of 15649 is 94651.

15649 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11025 + 4624 = 105^2 + 68^2 .

It is an emirp because it is prime and its reverse (94651) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 15649 - 2¹ = 15647 is a prime.

Together with 15647, it forms a pair of twin primes.

It is a plaindrome in base 14.

It is not a weakly prime, because it can be changed into another prime (15641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7824 + 7825.

It is an arithmetic number, because the mean of its divisors is an integer number (7825).

2¹⁵⁶⁴⁹ is an apocalyptic number.

It is an amenable number.

15649 is a deficient number, since it is larger than the sum of its proper divisors (1).

15649 is an equidigital number, since it uses as much as digits as its factorization.

15649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1080, while the sum is 25.

The square root of 15649 is about 125.0959631643. The cubic root of 15649 is about 25.0127934520.

The spelling of 15649 in words is "fifteen thousand, six hundred forty-nine".