1642 has 4 divisors (see below), whose sum is σ = 2466.
Its totient is φ = 820.
The previous prime is 1637. The next prime is 1657. The reversal of 1642 is 2461.
1642 is nontrivially palindromic in base 5 and base 15.
It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 2461 = 23 ⋅107.
It can be written as a sum of positive squares in only one way, i.e., 1521 + 121 = 39^2 + 11^2
It is a Smith number, since the sum of its digits (13) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.
1642 is an undulating number in base 15.
It is a plaindrome in base 6, base 9 and base 16.
It is a nialpdrome in base 13 and base 14.
It is an unprimeable number.
1642 is an untouchable number, because it is not equal to the sum of proper divisors of any number.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 409 + ... + 412.
21642 is an apocalyptic number.
1642 is a deficient number, since it is larger than the sum of its proper divisors (824).
1642 is an equidigital number, since it uses as much as digits as its factorization.
1642 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 823.
The product of its digits is 48, while the sum is 13.
The square root of 1642 is about 40.5215991787.
The cubic root of 1642 is about 11.7975289281.
The spelling of 1642 in words is "one thousand, six hundred forty-two".