221277216989 has 2 divisors, whose sum is σ = 221277216990. Its totient is φ = 221277216988.

The previous prime is 221277216973. The next prime is 221277216997. The reversal of 221277216989 is 989612772122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 211007016025 + 10270200964 = 459355^2 + 101342^2 .

It is a cyclic number.

It is not a de Polignac number, because 221277216989 - 2⁴ = 221277216973 is a prime.

It is a super-2 number, since 2×221277216989² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221279216989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110638608494 + 110638608495.

It is an arithmetic number, because the mean of its divisors is an integer number (110638608495).

Almost surely, 2^221277216989 is an apocalyptic number.

It is an amenable number.

221277216989 is a deficient number, since it is larger than the sum of its proper divisors (1).

221277216989 is an equidigital number, since it uses as much as digits as its factorization.

221277216989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3048192, while the sum is 56.

The spelling of 221277216989 in words is "two hundred twenty-one billion, two hundred seventy-seven million, two hundred sixteen thousand, nine hundred eighty-nine".