1664371 has 4 divisors (see below), whose sum is σ = 1709392. Its totient is φ = 1619352.

The previous prime is 1664353. The next prime is 1664387. The reversal of 1664371 is 1734661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1734661 = 251 ⋅6911.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1664371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1664071) 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, 22455 + ... + 22528.

It is an arithmetic number, because the mean of its divisors is an integer number (427348).

2^1664371 is an apocalyptic number.

1664371 is a deficient number, since it is larger than the sum of its proper divisors (45021).

1664371 is an equidigital number, since it uses as much as digits as its factorization.

1664371 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45020.

The product of its digits is 3024, while the sum is 28.

The square root of 1664371 is about 1290.1050344836. The cubic root of 1664371 is about 118.5086488610.

The spelling of 1664371 in words is "one million, six hundred sixty-four thousand, three hundred seventy-one".