221220505993 has 2 divisors, whose sum is σ = 221220505994. Its totient is φ = 221220505992.

The previous prime is 221220505927. The next prime is 221220506011. The reversal of 221220505993 is 399505022122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 193607040064 + 27613465929 = 440008^2 + 166173^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221220505993 is a prime.

It is not a weakly prime, because it can be changed into another prime (221220500993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110610252996 + 110610252997.

It is an arithmetic number, because the mean of its divisors is an integer number (110610252997).

Almost surely, 2^221220505993 is an apocalyptic number.

It is an amenable number.

221220505993 is a deficient number, since it is larger than the sum of its proper divisors (1).

221220505993 is an equidigital number, since it uses as much as digits as its factorization.

221220505993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 97200, while the sum is 40.

The spelling of 221220505993 in words is "two hundred twenty-one billion, two hundred twenty million, five hundred five thousand, nine hundred ninety-three".