1664378323 has 8 divisors (see below), whose sum is σ = 1677102336. Its totient is φ = 1651677000.

The previous prime is 1664378299. The next prime is 1664378329. The reversal of 1664378323 is 3238734661.

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 1664378323 - 2¹⁷ = 1664247251 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1664378323.

It is not an unprimeable number, because it can be changed into a prime (1664378329) 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, 159690 + ... + 169792.

It is an arithmetic number, because the mean of its divisors is an integer number (209637792).

Almost surely, 2^1664378323 is an apocalyptic number.

1664378323 is a deficient number, since it is larger than the sum of its proper divisors (12724013).

1664378323 is a wasteful number, since it uses less digits than its factorization.

1664378323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11345.

The product of its digits is 435456, while the sum is 43.

The square root of 1664378323 is about 40796.7930479836. The cubic root of 1664378323 is about 1185.0882266796.

The spelling of 1664378323 in words is "one billion, six hundred sixty-four million, three hundred seventy-eight thousand, three hundred twenty-three".