1664242161421 has 8 divisors (see below), whose sum is σ = 1904135345280. Its totient is φ = 1424885053488.

The previous prime is 1664242161409. The next prime is 1664242161437. The reversal of 1664242161421 is 1241612424661.

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 1664242161421 - 2¹³ = 1664242153229 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664242161521) 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, 134012326 + ... + 134024743.

It is an arithmetic number, because the mean of its divisors is an integer number (238016918160).

Almost surely, 2^{1664242161421} is an apocalyptic number.

It is an amenable number.

1664242161421 is a deficient number, since it is larger than the sum of its proper divisors (239893183859).

1664242161421 is an equidigital number, since it uses as much as digits as its factorization.

1664242161421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 268037963.

The product of its digits is 110592, while the sum is 40.

The spelling of 1664242161421 in words is "one trillion, six hundred sixty-four billion, two hundred forty-two million, one hundred sixty-one thousand, four hundred twenty-one".