20764609 has 8 divisors (see below), whose sum is σ = 21681000. Its totient is φ = 19861632.

The previous prime is 20764591. The next prime is 20764619. The reversal of 20764609 is 90646702.

It can be written as a sum of positive squares in 4 ways, for example, as 9394225 + 11370384 = 3065^2 + 3372^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20764609 - 2⁵ = 20764577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20764619) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 124 + ... + 6445.

It is an arithmetic number, because the mean of its divisors is an integer number (2710125).

Almost surely, 2^20764609 is an apocalyptic number.

20764609 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

20764609 is a deficient number, since it is larger than the sum of its proper divisors (916391).

20764609 is a wasteful number, since it uses less digits than its factorization.

20764609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6707.

The product of its (nonzero) digits is 18144, while the sum is 34.

The square root of 20764609 is about 4556.8200535022. The cubic root of 20764609 is about 274.8577071025.

The spelling of 20764609 in words is "twenty million, seven hundred sixty-four thousand, six hundred nine".