21220111223357 has 2 divisors, whose sum is σ = 21220111223358. Its totient is φ = 21220111223356.

The previous prime is 21220111223291. The next prime is 21220111223359. The reversal of 21220111223357 is 75332211102212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19535790044761 + 1684321178596 = 4419931^2 + 1297814^2 .

It is a cyclic number.

It is not a de Polignac number, because 21220111223357 - 2¹² = 21220111219261 is a prime.

Together with 21220111223359, 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 (21220111223359) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610055611678 + 10610055611679.

It is an arithmetic number, because the mean of its divisors is an integer number (10610055611679).

Almost surely, 2^{21220111223357} is an apocalyptic number.

It is an amenable number.

21220111223357 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220111223357 is an equidigital number, since it uses as much as digits as its factorization.

21220111223357 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10080, while the sum is 32.

Adding to 21220111223357 its reverse (75332211102212), we get a palindrome (96552322325569).

The spelling of 21220111223357 in words is "twenty-one trillion, two hundred twenty billion, one hundred eleven million, two hundred twenty-three thousand, three hundred fifty-seven".