221857455623957 has 2 divisors, whose sum is σ = 221857455623958. Its totient is φ = 221857455623956.

The previous prime is 221857455623917. The next prime is 221857455623959. The reversal of 221857455623957 is 759326554758122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 159556333296721 + 62301122327236 = 12631561^2 + 7893106^2 .

It is a cyclic number.

It is not a de Polignac number, because 221857455623957 - 2⁶ = 221857455623893 is a prime.

Together with 221857455623959, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221857455623959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110928727811978 + 110928727811979.

It is an arithmetic number, because the mean of its divisors is an integer number (110928727811979).

Almost surely, 2^{221857455623957} is an apocalyptic number.

It is an amenable number.

221857455623957 is a deficient number, since it is larger than the sum of its proper divisors (1).

221857455623957 is an equidigital number, since it uses as much as digits as its factorization.

221857455623957 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1270080000, while the sum is 71.

The spelling of 221857455623957 in words is "two hundred twenty-one trillion, eight hundred fifty-seven billion, four hundred fifty-five million, six hundred twenty-three thousand, nine hundred fifty-seven".