1664397 has 24 divisors (see below), whose sum is σ = 2845440. Its totient is φ = 917280.

The previous prime is 1664387. The next prime is 1664407. The reversal of 1664397 is 7934661.

1664397 is a `hidden beast` number, since 1 + 6 + 643 + 9 + 7 = 666.

It is an interprime number because it is at equal distance from previous prime (1664387) and next prime (1664407).

It is not a de Polignac number, because 1664397 - 2¹⁰ = 1663373 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664387) 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 23 ways as a sum of consecutive naturals, for example, 1372 + ... + 2282.

It is an arithmetic number, because the mean of its divisors is an integer number (118560).

2^1664397 is an apocalyptic number.

It is an amenable number.

1664397 is a deficient number, since it is larger than the sum of its proper divisors (1181043).

1664397 is a wasteful number, since it uses less digits than its factorization.

1664397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 953 (or 950 counting only the distinct ones).

The product of its digits is 27216, while the sum is 36.

The square root of 1664397 is about 1290.1151111432. The cubic root of 1664397 is about 118.5092659528.

The spelling of 1664397 in words is "one million, six hundred sixty-four thousand, three hundred ninety-seven".