661631549863 has 2 divisors, whose sum is σ = 661631549864. Its totient is φ = 661631549862.

The previous prime is 661631549819. The next prime is 661631549879. The reversal of 661631549863 is 368945136166.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661631549863 is a prime.

It is a super-3 number, since 3×661631549863³ (a number of 36 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 661631549798 and 661631549807.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661631549563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330815774931 + 330815774932.

It is an arithmetic number, because the mean of its divisors is an integer number (330815774932).

Almost surely, 2^661631549863 is an apocalyptic number.

661631549863 is a deficient number, since it is larger than the sum of its proper divisors (1).

661631549863 is an equidigital number, since it uses as much as digits as its factorization.

661631549863 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16796160, while the sum is 58.

The spelling of 661631549863 in words is "six hundred sixty-one billion, six hundred thirty-one million, five hundred forty-nine thousand, eight hundred sixty-three".