2905121221 has 2 divisors, whose sum is σ = 2905121222. Its totient is φ = 2905121220.

The previous prime is 2905121209. The next prime is 2905121239. The reversal of 2905121221 is 1221215092.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2772549025 + 132572196 = 52655^2 + 11514^2 .

It is a cyclic number.

It is not a de Polignac number, because 2905121221 - 2⁹ = 2905120709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2905121521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1452560610 + 1452560611.

It is an arithmetic number, because the mean of its divisors is an integer number (1452560611).

Almost surely, 2^2905121221 is an apocalyptic number.

It is an amenable number.

2905121221 is a deficient number, since it is larger than the sum of its proper divisors (1).

2905121221 is an equidigital number, since it uses as much as digits as its factorization.

2905121221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 2905121221 is about 53899.1764408326. The cubic root of 2905121221 is about 1426.8820882222.

The spelling of 2905121221 in words is "two billion, nine hundred five million, one hundred twenty-one thousand, two hundred twenty-one".