820634 has 4 divisors (see below), whose sum is σ = 1230954. Its totient is φ = 410316.

The previous prime is 820627. The next prime is 820637. The reversal of 820634 is 436028.

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., 727609 + 93025 = 853^2 + 305^2 .

It is not an unprimeable number, because it can be changed into a prime (820637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 205157 + ... + 205160.

2⁸²⁰⁶³⁴ is an apocalyptic number.

820634 is a deficient number, since it is larger than the sum of its proper divisors (410320).

820634 is a wasteful number, since it uses less digits than its factorization.

820634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 410319.

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 820634 is about 905.8885141120. Note that the first 3 decimals coincide. The cubic root of 820634 is about 93.6231326904.

The spelling of 820634 in words is "eight hundred twenty thousand, six hundred thirty-four".