642836 has 6 divisors (see below), whose sum is σ = 1124970. Its totient is φ = 321416.

The previous prime is 642833. The next prime is 642853. The reversal of 642836 is 638246.

642836 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 498436 + 144400 = 706^2 + 380^2 .

It is a junction number, because it is equal to n+sod(n) for n = 642799 and 642808.

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 642836.

It is not an unprimeable number, because it can be changed into a prime (642833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80351 + ... + 80358.

It is an arithmetic number, because the mean of its divisors is an integer number (187495).

2⁶⁴²⁸³⁶ is an apocalyptic number.

It is an amenable number.

642836 is a deficient number, since it is larger than the sum of its proper divisors (482134).

642836 is a wasteful number, since it uses less digits than its factorization.

642836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160713 (or 160711 counting only the distinct ones).

The product of its digits is 6912, while the sum is 29.

The square root of 642836 is about 801.7705407409. The cubic root of 642836 is about 86.3044912260.

The spelling of 642836 in words is "six hundred forty-two thousand, eight hundred thirty-six".