1664673469 has 4 divisors (see below), whose sum is σ = 1691963260. Its totient is φ = 1637383680.

The previous prime is 1664673463. The next prime is 1664673487. The reversal of 1664673469 is 9643764661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 950982244 + 713691225 = 30838^2 + 26715^2 .

It is a cyclic number.

It is not a de Polignac number, because 1664673469 - 2¹⁵ = 1664640701 is a prime.

It is a super-2 number, since 2×1664673469² = 5542275516784987922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664673463) 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, 13644804 + ... + 13644925.

It is an arithmetic number, because the mean of its divisors is an integer number (422990815).

Almost surely, 2^1664673469 is an apocalyptic number.

It is an amenable number.

1664673469 is a deficient number, since it is larger than the sum of its proper divisors (27289791).

1664673469 is an equidigital number, since it uses as much as digits as its factorization.

1664673469 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27289790.

The product of its digits is 3919104, while the sum is 52.

The square root of 1664673469 is about 40800.4101572521. The cubic root of 1664673469 is about 1185.1582735296.

The spelling of 1664673469 in words is "one billion, six hundred sixty-four million, six hundred seventy-three thousand, four hundred sixty-nine".