642650 has 12 divisors (see below), whose sum is σ = 1195422. Its totient is φ = 257040.

The previous prime is 642623. The next prime is 642673. The reversal of 642650 is 56246.

Added to its reverse (56246) it gives a square (698896 = 836²).

642650 = 53² + 54² + ... + 127².

It can be written as a sum of positive squares in 3 ways, for example, as 395641 + 247009 = 629^2 + 497^2 .

It is a Curzon number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 6377 + ... + 6476.

2⁶⁴²⁶⁵⁰ is an apocalyptic number.

642650 is a deficient number, since it is larger than the sum of its proper divisors (552772).

642650 is a wasteful number, since it uses less digits than its factorization.

642650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12865 (or 12860 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 642650 is about 801.6545390628. The cubic root of 642650 is about 86.2961665606.

Adding to 642650 its reverse (56246), we get a palindrome (698896).

The spelling of 642650 in words is "six hundred forty-two thousand, six hundred fifty".