43663537261 has 2 divisors, whose sum is σ = 43663537262. Its totient is φ = 43663537260.

The previous prime is 43663537219. The next prime is 43663537283. The reversal of 43663537261 is 16273536634.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43601616100 + 61921161 = 208810^2 + 7869^2 .

It is a cyclic number.

It is not a de Polignac number, because 43663537261 - 2³¹ = 41516053613 is a prime.

It is a super-2 number, since 2×43663537261² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43663537201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21831768630 + 21831768631.

It is an arithmetic number, because the mean of its divisors is an integer number (21831768631).

Almost surely, 2^43663537261 is an apocalyptic number.

It is an amenable number.

43663537261 is a deficient number, since it is larger than the sum of its proper divisors (1).

43663537261 is an equidigital number, since it uses as much as digits as its factorization.

43663537261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1632960, while the sum is 46.

The spelling of 43663537261 in words is "forty-three billion, six hundred sixty-three million, five hundred thirty-seven thousand, two hundred sixty-one".