1640489 has 4 divisors (see below), whose sum is σ = 1693440. Its totient is φ = 1587540.

The previous prime is 1640467. The next prime is 1640497. The reversal of 1640489 is 9840461.

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: 9840461 = 19 ⋅517919.

It is a cyclic number.

It is not a de Polignac number, because 1640489 - 2¹⁶ = 1574953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1640189) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26429 + ... + 26490.

It is an arithmetic number, because the mean of its divisors is an integer number (423360).

2^1640489 is an apocalyptic number.

It is an amenable number.

1640489 is a deficient number, since it is larger than the sum of its proper divisors (52951).

1640489 is an equidigital number, since it uses as much as digits as its factorization.

1640489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52950.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 1640489 is about 1280.8157556807. The cubic root of 1640489 is about 117.9390904648.

The spelling of 1640489 in words is "one million, six hundred forty thousand, four hundred eighty-nine".