355404221 has 2 divisors, whose sum is σ = 355404222. Its totient is φ = 355404220.

The previous prime is 355404157. The next prime is 355404229. The reversal of 355404221 is 122404553.

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., 350625625 + 4778596 = 18725^2 + 2186^2 .

It is a cyclic number.

It is not a de Polignac number, because 355404221 - 2⁶ = 355404157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (355404229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 177702110 + 177702111.

It is an arithmetic number, because the mean of its divisors is an integer number (177702111).

Almost surely, 2^355404221 is an apocalyptic number.

It is an amenable number.

355404221 is a deficient number, since it is larger than the sum of its proper divisors (1).

355404221 is an equidigital number, since it uses as much as digits as its factorization.

355404221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4800, while the sum is 26.

The square root of 355404221 is about 18852.1675411609. The cubic root of 355404221 is about 708.3385212569.

Adding to 355404221 its reverse (122404553), we get a palindrome (477808774).

The spelling of 355404221 in words is "three hundred fifty-five million, four hundred four thousand, two hundred twenty-one".