15649715909 has 2 divisors, whose sum is σ = 15649715910. Its totient is φ = 15649715908.

The previous prime is 15649715831. The next prime is 15649715929. The reversal of 15649715909 is 90951794651.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15607504900 + 42211009 = 124930^2 + 6497^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15649715909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15649715929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7824857954 + 7824857955.

It is an arithmetic number, because the mean of its divisors is an integer number (7824857955).

Almost surely, 2^15649715909 is an apocalyptic number.

It is an amenable number.

15649715909 is a deficient number, since it is larger than the sum of its proper divisors (1).

15649715909 is an equidigital number, since it uses as much as digits as its factorization.

15649715909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3061800, while the sum is 56.

The spelling of 15649715909 in words is "fifteen billion, six hundred forty-nine million, seven hundred fifteen thousand, nine hundred nine".