421021121 has 2 divisors, whose sum is σ = 421021122. Its totient is φ = 421021120.

The previous prime is 421021103. The next prime is 421021123. The reversal of 421021121 is 121120124.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 332661121 + 88360000 = 18239^2 + 9400^2 .

It is a cyclic number.

It is not a de Polignac number, because 421021121 - 2¹⁰ = 421020097 is a prime.

Together with 421021123, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 421021096 and 421021105.

It is not a weakly prime, because it can be changed into another prime (421021123) 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 as a sum of consecutive naturals, namely, 210510560 + 210510561.

It is an arithmetic number, because the mean of its divisors is an integer number (210510561).

Almost surely, 2^421021121 is an apocalyptic number.

It is an amenable number.

421021121 is a deficient number, since it is larger than the sum of its proper divisors (1).

421021121 is an equidigital number, since it uses as much as digits as its factorization.

421021121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 421021121 is about 20518.7992095054. The cubic root of 421021121 is about 749.4936558607.

Adding to 421021121 its reverse (121120124), we get a palindrome (542141245).

The spelling of 421021121 in words is "four hundred twenty-one million, twenty-one thousand, one hundred twenty-one".