1664985169 has 4 divisors (see below), whose sum is σ = 1718694400. Its totient is φ = 1611275940.

The previous prime is 1664985139. The next prime is 1664985173. The reversal of 1664985169 is 9615894661.

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 not a de Polignac number, because 1664985169 - 2¹¹ = 1664983121 is a prime.

It is a super-2 number, since 2×1664985169² = 5544351225979917122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1664985109) 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, 26854569 + ... + 26854630.

It is an arithmetic number, because the mean of its divisors is an integer number (429673600).

Almost surely, 2^1664985169 is an apocalyptic number.

It is an amenable number.

1664985169 is a deficient number, since it is larger than the sum of its proper divisors (53709231).

1664985169 is an equidigital number, since it uses as much as digits as its factorization.

1664985169 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53709230.

The product of its digits is 2799360, while the sum is 55.

The square root of 1664985169 is about 40804.2297930006. The cubic root of 1664985169 is about 1185.2322401436.

The spelling of 1664985169 in words is "one billion, six hundred sixty-four million, nine hundred eighty-five thousand, one hundred sixty-nine".