20645359 has 4 divisors (see below), whose sum is σ = 23594704. Its totient is φ = 17696016.

The previous prime is 20645347. The next prime is 20645399. The reversal of 20645359 is 95354602.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20645359 - 2⁹ = 20644847 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20645399) 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, 1474662 + ... + 1474675.

It is an arithmetic number, because the mean of its divisors is an integer number (5898676).

Almost surely, 2^20645359 is an apocalyptic number.

20645359 is a deficient number, since it is larger than the sum of its proper divisors (2949345).

20645359 is an equidigital number, since it uses as much as digits as its factorization.

20645359 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2949344.

The product of its (nonzero) digits is 32400, while the sum is 34.

The square root of 20645359 is about 4543.7164304124. The cubic root of 20645359 is about 274.3305324338.

The spelling of 20645359 in words is "twenty million, six hundred forty-five thousand, three hundred fifty-nine".