642319 has 4 divisors (see below), whose sum is σ = 647080. Its totient is φ = 637560.

The previous prime is 642281. The next prime is 642359. The reversal of 642319 is 913246.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 913246 = 2 ⋅456623.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642319 is a prime.

It is a super-2 number, since 2×642319² = 825147395522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 642293 and 642302.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642359) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2172 + ... + 2449.

It is an arithmetic number, because the mean of its divisors is an integer number (161770).

2⁶⁴²³¹⁹ is an apocalyptic number.

642319 is a deficient number, since it is larger than the sum of its proper divisors (4761).

642319 is a wasteful number, since it uses less digits than its factorization.

642319 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4760.

The product of its digits is 1296, while the sum is 25.

The square root of 642319 is about 801.4480644434. The cubic root of 642319 is about 86.2813482632.

It can be divided in two parts, 642 and 319, that added together give a square (961 = 31²).

The spelling of 642319 in words is "six hundred forty-two thousand, three hundred nineteen".