1664242361 has 4 divisors (see below), whose sum is σ = 1685308800. Its totient is φ = 1643175924.

The previous prime is 1664242339. The next prime is 1664242381. The reversal of 1664242361 is 1632424661.

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 a de Polignac number, because none of the positive numbers 2^k-1664242361 is a prime.

It is a super-3 number, since 3×1664242361³ (a number of 29 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1664242331) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10533101 + ... + 10533258.

It is an arithmetic number, because the mean of its divisors is an integer number (421327200).

Almost surely, 2^1664242361 is an apocalyptic number.

It is an amenable number.

1664242361 is a deficient number, since it is larger than the sum of its proper divisors (21066439).

1664242361 is an equidigital number, since it uses as much as digits as its factorization.

1664242361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21066438.

The product of its digits is 41472, while the sum is 35.

The square root of 1664242361 is about 40795.1266819948. The cubic root of 1664242361 is about 1185.0559561012.

The spelling of 1664242361 in words is "one billion, six hundred sixty-four million, two hundred forty-two thousand, three hundred sixty-one".