221277421 has 2 divisors, whose sum is σ = 221277422. Its totient is φ = 221277420.

The previous prime is 221277383. The next prime is 221277461. The reversal of 221277421 is 124772122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 160655625 + 60621796 = 12675^2 + 7786^2 .

It is a cyclic number.

It is not a de Polignac number, because 221277421 - 2²³ = 212888813 is a prime.

It is a super-2 number, since 2×221277421² = 97927394088822482, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 221277421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221277461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110638710 + 110638711.

It is an arithmetic number, because the mean of its divisors is an integer number (110638711).

Almost surely, 2^221277421 is an apocalyptic number.

It is an amenable number.

221277421 is a deficient number, since it is larger than the sum of its proper divisors (1).

221277421 is an equidigital number, since it uses as much as digits as its factorization.

221277421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3136, while the sum is 28.

The square root of 221277421 is about 14875.3964989173. The cubic root of 221277421 is about 604.8472359786.

The spelling of 221277421 in words is "two hundred twenty-one million, two hundred seventy-seven thousand, four hundred twenty-one".