642493 has 4 divisors (see below), whose sum is σ = 647680. Its totient is φ = 637308.

The previous prime is 642487. The next prime is 642517. The reversal of 642493 is 394246.

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: 394246 = 2 ⋅197123.

It is a cyclic number.

It is not a de Polignac number, because 642493 - 2⁹ = 641981 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 (642403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2403 + ... + 2656.

It is an arithmetic number, because the mean of its divisors is an integer number (161920).

2⁶⁴²⁴⁹³ is an apocalyptic number.

It is an amenable number.

642493 is a deficient number, since it is larger than the sum of its proper divisors (5187).

642493 is a wasteful number, since it uses less digits than its factorization.

642493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5186.

The product of its digits is 5184, while the sum is 28.

The square root of 642493 is about 801.5566106021. The cubic root of 642493 is about 86.2891385767.

The spelling of 642493 in words is "six hundred forty-two thousand, four hundred ninety-three".