20982121 has 4 divisors (see below), whose sum is σ = 21013972. Its totient is φ = 20950272.

The previous prime is 20982107. The next prime is 20982127. The reversal of 20982121 is 12128902.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11594025 + 9388096 = 3405^2 + 3064^2 .

It is a cyclic number.

It is not a de Polignac number, because 20982121 - 2⁵ = 20982089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20982127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14916 + ... + 16261.

It is an arithmetic number, because the mean of its divisors is an integer number (5253493).

Almost surely, 2^20982121 is an apocalyptic number.

It is an amenable number.

20982121 is a deficient number, since it is larger than the sum of its proper divisors (31851).

20982121 is an equidigital number, since it uses as much as digits as its factorization.

20982121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31850.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 20982121 is about 4580.6245207395. The cubic root of 20982121 is about 275.8140988911.

The spelling of 20982121 in words is "twenty million, nine hundred eighty-two thousand, one hundred twenty-one".