1664401 has 4 divisors (see below), whose sum is σ = 1703152. Its totient is φ = 1625652.

The previous prime is 1664387. The next prime is 1664407. The reversal of 1664401 is 1044661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1044661 = 211 ⋅4951.

It is a cyclic number.

It is not a de Polignac number, because 1664401 - 2¹³ = 1656209 is a prime.

It is a pancake number, because a pancake can be divided into 1664401 parts by 1824 straight cuts.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1664407) 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, 19311 + ... + 19396.

It is an arithmetic number, because the mean of its divisors is an integer number (425788).

2^1664401 is an apocalyptic number.

It is an amenable number.

1664401 is a deficient number, since it is larger than the sum of its proper divisors (38751).

1664401 is an equidigital number, since it uses as much as digits as its factorization.

1664401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38750.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 1664401 is about 1290.1166613915. The cubic root of 1664401 is about 118.5093608894.

The spelling of 1664401 in words is "one million, six hundred sixty-four thousand, four hundred one".