20425009 has 4 divisors (see below), whose sum is σ = 22281840. Its totient is φ = 18568180.

The previous prime is 20424983. The next prime is 20425021. The reversal of 20425009 is 90052402.

It is a happy number.

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 20425009 - 2⁵ = 20424977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20425049) 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, 928399 + ... + 928420.

It is an arithmetic number, because the mean of its divisors is an integer number (5570460).

Almost surely, 2^20425009 is an apocalyptic number.

It is an amenable number.

20425009 is a deficient number, since it is larger than the sum of its proper divisors (1856831).

20425009 is a wasteful number, since it uses less digits than its factorization.

20425009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1856830.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 20425009 is about 4519.4036110974. The cubic root of 20425009 is about 273.3510536135.

The spelling of 20425009 in words is "twenty million, four hundred twenty-five thousand, nine".