1664417 has 2 divisors, whose sum is σ = 1664418. Its totient is φ = 1664416.

The previous prime is 1664407. The next prime is 1664431. The reversal of 1664417 is 7144661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1478656 + 185761 = 1216^2 + 431^2 .

It is a cyclic number.

It is not a de Polignac number, because 1664417 - 2⁶ = 1664353 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1664417.

It is not a weakly prime, because it can be changed into another prime (1664407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832208 + 832209.

It is an arithmetic number, because the mean of its divisors is an integer number (832209).

2^1664417 is an apocalyptic number.

It is an amenable number.

1664417 is a deficient number, since it is larger than the sum of its proper divisors (1).

1664417 is an equidigital number, since it uses as much as digits as its factorization.

1664417 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4032, while the sum is 29.

The square root of 1664417 is about 1290.1228623662. The cubic root of 1664417 is about 118.5097406344.

It can be divided in two parts, 16644 and 17, that added together give a palindrome (16661).

The spelling of 1664417 in words is "one million, six hundred sixty-four thousand, four hundred seventeen".