1663966321057 has 4 divisors (see below), whose sum is σ = 1687402466496. Its totient is φ = 1640530175620.

The previous prime is 1663966321037. The next prime is 1663966321063. The reversal of 1663966321057 is 7501236693661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1663966321057 - 2¹¹ = 1663966319009 is a prime.

It is a super-2 number, since 2×1663966321057² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1663966320989 and 1663966321007.

It is not an unprimeable number, because it can be changed into a prime (1663966321037) 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 in 3 ways as a sum of consecutive naturals, for example, 11718072613 + ... + 11718072754.

It is an arithmetic number, because the mean of its divisors is an integer number (421850616624).

Almost surely, 2^{1663966321057} is an apocalyptic number.

It is an amenable number.

1663966321057 is a deficient number, since it is larger than the sum of its proper divisors (23436145439).

1663966321057 is an equidigital number, since it uses as much as digits as its factorization.

1663966321057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23436145438.

The product of its (nonzero) digits is 7348320, while the sum is 55.

The spelling of 1663966321057 in words is "one trillion, six hundred sixty-three billion, nine hundred sixty-six million, three hundred twenty-one thousand, fifty-seven".