1663667644745 has 8 divisors (see below), whose sum is σ = 1996425181320. Its totient is φ = 1330918110720.

The previous prime is 1663667644699. The next prime is 1663667644747. The reversal of 1663667644745 is 5474467663661.

It can be written as a sum of positive squares in 4 ways, for example, as 9295466569 + 1654372178176 = 96413^2 + 1286224^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1663667644745 - 2¹⁴ = 1663667628361 is a prime.

It is a super-2 number, since 2×1663667644745² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1663667644747) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1533350 + ... + 2382959.

It is an arithmetic number, because the mean of its divisors is an integer number (249553147665).

Almost surely, 2^{1663667644745} is an apocalyptic number.

It is an amenable number.

1663667644745 is a deficient number, since it is larger than the sum of its proper divisors (332757536575).

1663667644745 is an equidigital number, since it uses as much as digits as its factorization.

1663667644745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4001275.

The product of its digits is 365783040, while the sum is 65.

The spelling of 1663667644745 in words is "one trillion, six hundred sixty-three billion, six hundred sixty-seven million, six hundred forty-four thousand, seven hundred forty-five".