20475121 has 2 divisors, whose sum is σ = 20475122. Its totient is φ = 20475120.

The previous prime is 20475107. The next prime is 20475149. The reversal of 20475121 is 12157402.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16313521 + 4161600 = 4039^2 + 2040^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20475121 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20475092 and 20475101.

It is not a weakly prime, because it can be changed into another prime (20475101) 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 as a sum of consecutive naturals, namely, 10237560 + 10237561.

It is an arithmetic number, because the mean of its divisors is an integer number (10237561).

Almost surely, 2^20475121 is an apocalyptic number.

It is an amenable number.

20475121 is a deficient number, since it is larger than the sum of its proper divisors (1).

20475121 is an equidigital number, since it uses as much as digits as its factorization.

20475121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 20475121 is about 4524.9443090496. The cubic root of 20475121 is about 273.5744232515.

The spelling of 20475121 in words is "twenty million, four hundred seventy-five thousand, one hundred twenty-one".