20645323 has 4 divisors (see below), whose sum is σ = 20760840. Its totient is φ = 20529808.

The previous prime is 20645321. The next prime is 20645341. The reversal of 20645323 is 32354602.

It is a happy number.

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 20645323 - 2¹ = 20645321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20645321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57490 + ... + 57847.

It is an arithmetic number, because the mean of its divisors is an integer number (5190210).

Almost surely, 2^20645323 is an apocalyptic number.

20645323 is a deficient number, since it is larger than the sum of its proper divisors (115517).

20645323 is a wasteful number, since it uses less digits than its factorization.

20645323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115516.

The product of its (nonzero) digits is 4320, while the sum is 25.

The square root of 20645323 is about 4543.7124688959. The cubic root of 20645323 is about 274.3303729806.

Adding to 20645323 its reverse (32354602), we get a palindrome (52999925).

The spelling of 20645323 in words is "twenty million, six hundred forty-five thousand, three hundred twenty-three".