538640689 has 4 divisors (see below), whose sum is σ = 539409780. Its totient is φ = 537871600.

The previous prime is 538640681. The next prime is 538640731. The reversal of 538640689 is 986046835.

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 2 ways, for example, as 474368400 + 64272289 = 21780^2 + 8017^2 .

It is a cyclic number.

It is not a de Polignac number, because 538640689 - 2³ = 538640681 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (538640681) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 383494 + ... + 384895.

It is an arithmetic number, because the mean of its divisors is an integer number (134852445).

Almost surely, 2^538640689 is an apocalyptic number.

It is an amenable number.

538640689 is a deficient number, since it is larger than the sum of its proper divisors (769091).

538640689 is an equidigital number, since it uses as much as digits as its factorization.

538640689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 769090.

The product of its (nonzero) digits is 1244160, while the sum is 49.

The square root of 538640689 is about 23208.6339322244. The cubic root of 538640689 is about 813.6414260803.

The spelling of 538640689 in words is "five hundred thirty-eight million, six hundred forty thousand, six hundred eighty-nine".