121404221 has 2 divisors, whose sum is σ = 121404222. Its totient is φ = 121404220.

The previous prime is 121404211. The next prime is 121404229. The reversal of 121404221 is 122404121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69722500 + 51681721 = 8350^2 + 7189^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121404221 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 121404221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121404229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60702110 + 60702111.

It is an arithmetic number, because the mean of its divisors is an integer number (60702111).

Almost surely, 2^121404221 is an apocalyptic number.

It is an amenable number.

121404221 is a deficient number, since it is larger than the sum of its proper divisors (1).

121404221 is an equidigital number, since it uses as much as digits as its factorization.

121404221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 121404221 is about 11018.3583622970. The cubic root of 121404221 is about 495.1589069111.

Adding to 121404221 its reverse (122404121), we get a palindrome (243808342).

It can be divided in two parts, 12140 and 4221, that added together give a palindrome (16361).

The spelling of 121404221 in words is "one hundred twenty-one million, four hundred four thousand, two hundred twenty-one".