1664645260523 has 8 divisors (see below), whose sum is σ = 1902525294048. Its totient is φ = 1426783618944.

The previous prime is 1664645260471. The next prime is 1664645260651. The reversal of 1664645260523 is 3250625464661.

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

It is a cyclic number.

It is not a de Polignac number, because 1664645260523 - 2⁴⁰ = 565133632747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1664645265523) 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, 4403486 + ... + 4766547.

It is an arithmetic number, because the mean of its divisors is an integer number (237815661756).

Almost surely, 2^{1664645260523} is an apocalyptic number.

1664645260523 is a deficient number, since it is larger than the sum of its proper divisors (237880033525).

1664645260523 is an equidigital number, since it uses as much as digits as its factorization.

1664645260523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9195973.

The product of its (nonzero) digits is 6220800, while the sum is 50.

The spelling of 1664645260523 in words is "one trillion, six hundred sixty-four billion, six hundred forty-five million, two hundred sixty thousand, five hundred twenty-three".