15663663409 has 2 divisors, whose sum is σ = 15663663410. Its totient is φ = 15663663408.

The previous prime is 15663663397. The next prime is 15663663451. The reversal of 15663663409 is 90436636651.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11972736400 + 3690927009 = 109420^2 + 60753^2 .

It is a cyclic number.

It is not a de Polignac number, because 15663663409 - 2²⁷ = 15529445681 is a prime.

It is not a weakly prime, because it can be changed into another prime (15663663469) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7831831704 + 7831831705.

It is an arithmetic number, because the mean of its divisors is an integer number (7831831705).

Almost surely, 2^15663663409 is an apocalyptic number.

It is an amenable number.

15663663409 is a deficient number, since it is larger than the sum of its proper divisors (1).

15663663409 is an equidigital number, since it uses as much as digits as its factorization.

15663663409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2099520, while the sum is 49.

The spelling of 15663663409 in words is "fifteen billion, six hundred sixty-three million, six hundred sixty-three thousand, four hundred nine".