1664361 has 8 divisors (see below), whose sum is σ = 2465760. Its totient is φ = 1109556.

The previous prime is 1664353. The next prime is 1664387. The reversal of 1664361 is 1634661.

1664361 is a `hidden beast` number, since 16 + 643 + 6 + 1 = 666.

It is not a de Polignac number, because 1664361 - 2³ = 1664353 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 61643 = 1664361 / (1 + 6 + 6 + 4 + 3 + 6 + 1).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1664261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30795 + ... + 30848.

It is an arithmetic number, because the mean of its divisors is an integer number (308220).

2^1664361 is an apocalyptic number.

It is an amenable number.

1664361 is a deficient number, since it is larger than the sum of its proper divisors (801399).

1664361 is an equidigital number, since it uses as much as digits as its factorization.

1664361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61652 (or 61646 counting only the distinct ones).

The product of its digits is 2592, while the sum is 27.

The square root of 1664361 is about 1290.1011588244. The cubic root of 1664361 is about 118.5084115164.

It can be divided in two parts, 1664 and 361, that added together give a square (2025 = 45²).

The spelling of 1664361 in words is "one million, six hundred sixty-four thousand, three hundred sixty-one".