690820 has 24 divisors (see below), whose sum is σ = 1562904. Its totient is φ = 254976.

The previous prime is 690817. The next prime is 690839. The reversal of 690820 is 28096.

It can be written as a sum of positive squares in 4 ways, for example, as 28224 + 662596 = 168^2 + 814^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1069 + ... + 1588.

It is an arithmetic number, because the mean of its divisors is an integer number (65121).

2⁶⁹⁰⁸²⁰ is an apocalyptic number.

It is an amenable number.

690820 is an abundant number, since it is smaller than the sum of its proper divisors (872084).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

690820 is a wasteful number, since it uses less digits than its factorization.

690820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2679 (or 2677 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 690820 is about 831.1558217326. The cubic root of 690820 is about 88.4005500809.

The spelling of 690820 in words is "six hundred ninety thousand, eight hundred twenty".