221220021110021 has 2 divisors, whose sum is σ = 221220021110022. Its totient is φ = 221220021110020.

The previous prime is 221220021109999. The next prime is 221220021110041. The reversal of 221220021110021 is 120011120022122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 217696745702500 + 3523275407521 = 14754550^2 + 1877039^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221220021110021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221220021110041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110610010555010 + 110610010555011.

It is an arithmetic number, because the mean of its divisors is an integer number (110610010555011).

Almost surely, 2^{221220021110021} is an apocalyptic number.

It is an amenable number.

221220021110021 is a deficient number, since it is larger than the sum of its proper divisors (1).

221220021110021 is an equidigital number, since it uses as much as digits as its factorization.

221220021110021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 221220021110021 its reverse (120011120022122), we get a palindrome (341231141132143).

The spelling of 221220021110021 in words is "two hundred twenty-one trillion, two hundred twenty billion, twenty-one million, one hundred ten thousand, twenty-one".