402220121 has 2 divisors, whose sum is σ = 402220122. Its totient is φ = 402220120.

The previous prime is 402220079. The next prime is 402220123. The reversal of 402220121 is 121022204.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 225330121 + 176890000 = 15011^2 + 13300^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-402220121 is a prime.

Together with 402220123, 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 = 402220096 and 402220105.

It is not a weakly prime, because it can be changed into another prime (402220123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 201110060 + 201110061.

It is an arithmetic number, because the mean of its divisors is an integer number (201110061).

Almost surely, 2^402220121 is an apocalyptic number.

It is an amenable number.

402220121 is a deficient number, since it is larger than the sum of its proper divisors (1).

402220121 is an equidigital number, since it uses as much as digits as its factorization.

402220121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 402220121 is about 20055.4262233441. The cubic root of 402220121 is about 738.1669514307.

Adding to 402220121 its reverse (121022204), we get a palindrome (523242325).

The spelling of 402220121 in words is "four hundred two million, two hundred twenty thousand, one hundred twenty-one".