1664597 has 6 divisors (see below), whose sum is σ = 1829814. Its totient is φ = 1513160.

The previous prime is 1664569. The next prime is 1664627. The reversal of 1664597 is 7954661.

It can be written as a sum of positive squares in only one way, i.e., 1002001 + 662596 = 1001^2 + 814^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1664597 is a prime.

It is an Ulam number.

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 1664597.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664557) 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 5 ways as a sum of consecutive naturals, for example, 6758 + ... + 6999.

It is an arithmetic number, because the mean of its divisors is an integer number (304969).

2^1664597 is an apocalyptic number.

It is an amenable number.

1664597 is a deficient number, since it is larger than the sum of its proper divisors (165217).

1664597 is a wasteful number, since it uses less digits than its factorization.

1664597 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13779 (or 13768 counting only the distinct ones).

The product of its digits is 45360, while the sum is 38.

The square root of 1664597 is about 1290.1926212779. The cubic root of 1664597 is about 118.5140125975.

Subtracting 1664597 from its reverse (7954661), we obtain a square (6290064 = 2508²).

The spelling of 1664597 in words is "one million, six hundred sixty-four thousand, five hundred ninety-seven".