1663366633661 has 4 divisors (see below), whose sum is σ = 1663861539324. Its totient is φ = 1662871728000.

The previous prime is 1663366633657. The next prime is 1663366633679.

1663366633661 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1162924992100 + 500441641561 = 1078390^2 + 707419^2 .

It is a cyclic number.

It is not a de Polignac number, because 1663366633661 - 2² = 1663366633657 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1663366633597 and 1663366633606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1663366633601) 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 in 3 ways as a sum of consecutive naturals, for example, 247447790 + ... + 247454511.

It is an arithmetic number, because the mean of its divisors is an integer number (415965384831).

Almost surely, 2^{1663366633661} is an apocalyptic number.

It is an amenable number.

1663366633661 is a deficient number, since it is larger than the sum of its proper divisors (494905663).

1663366633661 is an equidigital number, since it uses as much as digits as its factorization.

1663366633661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 494905662.

The product of its digits is 22674816, while the sum is 56.

The spelling of 1663366633661 in words is "one trillion, six hundred sixty-three billion, three hundred sixty-six million, six hundred thirty-three thousand, six hundred sixty-one".