20506345 has 8 divisors (see below), whose sum is σ = 25401600. Its totient is φ = 15875760.

The previous prime is 20506337. The next prime is 20506349. The reversal of 20506345 is 54360502.

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

It is not a de Polignac number, because 20506345 - 2³ = 20506337 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20506349) 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, 65995 + ... + 66304.

It is an arithmetic number, because the mean of its divisors is an integer number (3175200).

Almost surely, 2^20506345 is an apocalyptic number.

It is an amenable number.

20506345 is a deficient number, since it is larger than the sum of its proper divisors (4895255).

20506345 is a wasteful number, since it uses less digits than its factorization.

20506345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132335.

The product of its (nonzero) digits is 3600, while the sum is 25.

The square root of 20506345 is about 4528.3932028922. The cubic root of 20506345 is about 273.7134171279.

Adding to 20506345 its reverse (54360502), we get a palindrome (74866847).

The spelling of 20506345 in words is "twenty million, five hundred six thousand, three hundred forty-five".