20648409 has 4 divisors (see below), whose sum is σ = 27531216. Its totient is φ = 13765604.

The previous prime is 20648401. The next prime is 20648413. The reversal of 20648409 is 90484602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20648409 - 2³ = 20648401 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20648409.

It is not an unprimeable number, because it can be changed into a prime (20648401) 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, 3441399 + ... + 3441404.

It is an arithmetic number, because the mean of its divisors is an integer number (6882804).

Almost surely, 2^20648409 is an apocalyptic number.

It is an amenable number.

20648409 is a deficient number, since it is larger than the sum of its proper divisors (6882807).

20648409 is an equidigital number, since it uses as much as digits as its factorization.

20648409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6882806.

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 20648409 is about 4544.0520463569. The cubic root of 20648409 is about 274.3440409891.

The spelling of 20648409 in words is "twenty million, six hundred forty-eight thousand, four hundred nine".