15645952909 has 2 divisors, whose sum is σ = 15645952910. Its totient is φ = 15645952908.

The previous prime is 15645952901. The next prime is 15645952919. The reversal of 15645952909 is 90925954651.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13896873225 + 1749079684 = 117885^2 + 41822^2 .

It is a cyclic number.

It is not a de Polignac number, because 15645952909 - 2³ = 15645952901 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 15645952909.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15645952901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7822976454 + 7822976455.

It is an arithmetic number, because the mean of its divisors is an integer number (7822976455).

Almost surely, 2^15645952909 is an apocalyptic number.

It is an amenable number.

15645952909 is a deficient number, since it is larger than the sum of its proper divisors (1).

15645952909 is an equidigital number, since it uses as much as digits as its factorization.

15645952909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4374000, while the sum is 55.

It can be divided in two parts, 1564595 and 2909, that added together give a square (1567504 = 1252²).

The spelling of 15645952909 in words is "fifteen billion, six hundred forty-five million, nine hundred fifty-two thousand, nine hundred nine".