20491121 has 4 divisors (see below), whose sum is σ = 23418432. Its totient is φ = 17563812.

The previous prime is 20491111. The next prime is 20491127. The reversal of 20491121 is 12119402.

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 not a de Polignac number, because 20491121 - 2⁶ = 20491057 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20491093 and 20491102.

It is not an unprimeable number, because it can be changed into a prime (20491127) 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, 1463645 + ... + 1463658.

It is an arithmetic number, because the mean of its divisors is an integer number (5854608).

Almost surely, 2^20491121 is an apocalyptic number.

It is an amenable number.

20491121 is a deficient number, since it is larger than the sum of its proper divisors (2927311).

20491121 is an equidigital number, since it uses as much as digits as its factorization.

20491121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2927310.

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 20491121 is about 4526.7119413543. The cubic root of 20491121 is about 273.6456650136.

The spelling of 20491121 in words is "twenty million, four hundred ninety-one thousand, one hundred twenty-one".