1642643 has 4 divisors (see below), whose sum is σ = 1680888. Its totient is φ = 1604400.

The previous prime is 1642633. The next prime is 1642649. The reversal of 1642643 is 3462461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3462461 = 131 ⋅26431.

It is a cyclic number.

It is not a de Polignac number, because 1642643 - 2⁶ = 1642579 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1642649) 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, 19058 + ... + 19143.

It is an arithmetic number, because the mean of its divisors is an integer number (420222).

2^1642643 is an apocalyptic number.

1642643 is a deficient number, since it is larger than the sum of its proper divisors (38245).

1642643 is an equidigital number, since it uses as much as digits as its factorization.

1642643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38244.

The product of its digits is 3456, while the sum is 26.

The square root of 1642643 is about 1281.6563501969. The cubic root of 1642643 is about 117.9906868069.

The spelling of 1642643 in words is "one million, six hundred forty-two thousand, six hundred forty-three".