642949 has 4 divisors (see below), whose sum is σ = 660364. Its totient is φ = 625536.

The previous prime is 642947. The next prime is 642953. The reversal of 642949 is 949246.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 294849 + 348100 = 543^2 + 590^2 .

It is a cyclic number.

It is not a de Polignac number, because 642949 - 2¹ = 642947 is a prime.

It is a Duffinian number.

642949 is a lucky number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 642949.

It is not an unprimeable number, because it can be changed into a prime (642947) 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, 8652 + ... + 8725.

It is an arithmetic number, because the mean of its divisors is an integer number (165091).

2⁶⁴²⁹⁴⁹ is an apocalyptic number.

It is an amenable number.

642949 is a deficient number, since it is larger than the sum of its proper divisors (17415).

642949 is a wasteful number, since it uses less digits than its factorization.

642949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17414.

The product of its digits is 15552, while the sum is 34.

The square root of 642949 is about 801.8410066840. The cubic root of 642949 is about 86.3095479000.

The spelling of 642949 in words is "six hundred forty-two thousand, nine hundred forty-nine".