220686989821 has 2 divisors, whose sum is σ = 220686989822. Its totient is φ = 220686989820.

The previous prime is 220686989741. The next prime is 220686989837. The reversal of 220686989821 is 128989686022.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 189821419225 + 30865570596 = 435685^2 + 175686^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-220686989821 is a prime.

It is a super-2 number, since 2×220686989821² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 220686989821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (220686989881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110343494910 + 110343494911.

It is an arithmetic number, because the mean of its divisors is an integer number (110343494911).

Almost surely, 2^220686989821 is an apocalyptic number.

It is an amenable number.

220686989821 is a deficient number, since it is larger than the sum of its proper divisors (1).

220686989821 is an equidigital number, since it uses as much as digits as its factorization.

220686989821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11943936, while the sum is 61.

The spelling of 220686989821 in words is "two hundred twenty billion, six hundred eighty-six million, nine hundred eighty-nine thousand, eight hundred twenty-one".