15663724261 has 2 divisors, whose sum is σ = 15663724262. Its totient is φ = 15663724260.

The previous prime is 15663724207. The next prime is 15663724273. The reversal of 15663724261 is 16242736651.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10426452100 + 5237272161 = 102110^2 + 72369^2 .

It is a cyclic number.

It is not a de Polignac number, because 15663724261 - 2⁷ = 15663724133 is a prime.

It is a super-2 number, since 2×15663724261² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15663724291) 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, 7831862130 + 7831862131.

It is an arithmetic number, because the mean of its divisors is an integer number (7831862131).

Almost surely, 2^15663724261 is an apocalyptic number.

It is an amenable number.

15663724261 is a deficient number, since it is larger than the sum of its proper divisors (1).

15663724261 is an equidigital number, since it uses as much as digits as its factorization.

15663724261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 362880, while the sum is 43.

The spelling of 15663724261 in words is "fifteen billion, six hundred sixty-three million, seven hundred twenty-four thousand, two hundred sixty-one".