221857455623257 has 2 divisors, whose sum is σ = 221857455623258. Its totient is φ = 221857455623256.

The previous prime is 221857455623179. The next prime is 221857455623329. The reversal of 221857455623257 is 752326554758122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 128809130046921 + 93048325576336 = 11349411^2 + 9646156^2 .

It is a cyclic number.

It is not a de Polignac number, because 221857455623257 - 2¹⁹ = 221857455098969 is a prime.

It is not a weakly prime, because it can be changed into another prime (221857455623957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110928727811628 + 110928727811629.

It is an arithmetic number, because the mean of its divisors is an integer number (110928727811629).

Almost surely, 2^{221857455623257} is an apocalyptic number.

It is an amenable number.

221857455623257 is a deficient number, since it is larger than the sum of its proper divisors (1).

221857455623257 is an equidigital number, since it uses as much as digits as its factorization.

221857455623257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 282240000, while the sum is 64.

The spelling of 221857455623257 in words is "two hundred twenty-one trillion, eight hundred fifty-seven billion, four hundred fifty-five million, six hundred twenty-three thousand, two hundred fifty-seven".