20239121 has 4 divisors (see below), whose sum is σ = 23130432. Its totient is φ = 17347812.

The previous prime is 20239099. The next prime is 20239127. The reversal of 20239121 is 12193202.

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 a de Polignac number, because none of the positive numbers 2^k-20239121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20239093 and 20239102.

It is not an unprimeable number, because it can be changed into a prime (20239127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1445645 + ... + 1445658.

It is an arithmetic number, because the mean of its divisors is an integer number (5782608).

Almost surely, 2^20239121 is an apocalyptic number.

It is an amenable number.

20239121 is a deficient number, since it is larger than the sum of its proper divisors (2891311).

20239121 is an equidigital number, since it uses as much as digits as its factorization.

20239121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2891310.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 20239121 is about 4498.7910598293. The cubic root of 20239121 is about 272.5192691814.

The spelling of 20239121 in words is "twenty million, two hundred thirty-nine thousand, one hundred twenty-one".