823642 has 4 divisors (see below), whose sum is σ = 1235466. Its totient is φ = 411820.

The previous prime is 823637. The next prime is 823643. The reversal of 823642 is 246328.

It is a happy number.

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

It can be written as a sum of positive squares in only one way, i.e., 670761 + 152881 = 819^2 + 391^2 .

It is a super-2 number, since 2×823642² = 1356772288328, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (823643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 205909 + ... + 205912.

2⁸²³⁶⁴² is an apocalyptic number.

823642 is a deficient number, since it is larger than the sum of its proper divisors (411824).

823642 is a wasteful number, since it uses less digits than its factorization.

823642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 411823.

The product of its digits is 2304, while the sum is 25.

The square root of 823642 is about 907.5472439493. The cubic root of 823642 is about 93.7373837838.

The spelling of 823642 in words is "eight hundred twenty-three thousand, six hundred forty-two".