209764 has 9 divisors (see below), whose sum is σ = 368697. Its totient is φ = 104424.

The previous prime is 209743. The next prime is 209767. The reversal of 209764 is 467902.

209764 = T₄₅₇ + T₄₅₈.

The square root of 209764 is 458.

It is a perfect power (a square), and thus also a powerful number.

209764 is digitally balanced in base 2 and base 3, because in such bases 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., 195364 + 14400 = 442^2 + 120^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (209767) by changing a digit.

209764 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 802 + ... + 1030.

209764 is a Friedman number, since it can be written as (467-9)^(2+0), using all its digits and the basic arithmetic operations.

2²⁰⁹⁷⁶⁴ is an apocalyptic number.

209764 is the 458-th square number.

It is an amenable number.

209764 is a deficient number, since it is larger than the sum of its proper divisors (158933).

209764 is an equidigital number, since it uses as much as digits as its factorization.

209764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 462 (or 231 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 28.

The cubic root of 209764 is about 59.4169450611.

The spelling of 209764 in words is "two hundred nine thousand, seven hundred sixty-four".