356540221 has 2 divisors, whose sum is σ = 356540222. Its totient is φ = 356540220.

The previous prime is 356540213. The next prime is 356540279. The reversal of 356540221 is 122045653.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 256320100 + 100220121 = 16010^2 + 10011^2 .

It is a cyclic number.

It is not a de Polignac number, because 356540221 - 2³ = 356540213 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 356540221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (356540321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 178270110 + 178270111.

It is an arithmetic number, because the mean of its divisors is an integer number (178270111).

Almost surely, 2^356540221 is an apocalyptic number.

It is an amenable number.

356540221 is a deficient number, since it is larger than the sum of its proper divisors (1).

356540221 is an equidigital number, since it uses as much as digits as its factorization.

356540221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7200, while the sum is 28.

The square root of 356540221 is about 18882.2726651216. The cubic root of 356540221 is about 709.0924203298.

Adding to 356540221 its reverse (122045653), we get a palindrome (478585874).

The spelling of 356540221 in words is "three hundred fifty-six million, five hundred forty thousand, two hundred twenty-one".