1640563 has 4 divisors (see below), whose sum is σ = 1643328. Its totient is φ = 1637800.

The previous prime is 1640557. The next prime is 1640599. The reversal of 1640563 is 3650461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3650461 = 17 ⋅214733.

It is a cyclic number.

It is not a de Polignac number, because 1640563 - 2⁵ = 1640531 is a prime.

It is a Duffinian number.

1640563 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1640503) 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, 88 + ... + 1813.

It is an arithmetic number, because the mean of its divisors is an integer number (410832).

2^1640563 is an apocalyptic number.

1640563 is a deficient number, since it is larger than the sum of its proper divisors (2765).

1640563 is an equidigital number, since it uses as much as digits as its factorization.

1640563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2764.

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 1640563 is about 1280.8446431945. The cubic root of 1640563 is about 117.9408637900.

The spelling of 1640563 in words is "one million, six hundred forty thousand, five hundred sixty-three".