221723969 has 2 divisors, whose sum is σ = 221723970. Its totient is φ = 221723968.

The previous prime is 221723917. The next prime is 221723989. The reversal of 221723969 is 969327122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 186677569 + 35046400 = 13663^2 + 5920^2 .

It is a cyclic number.

It is not a de Polignac number, because 221723969 - 2¹⁶ = 221658433 is a prime.

It is a super-2 number, since 2×221723969² = 98323036858225922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (221723989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110861984 + 110861985.

It is an arithmetic number, because the mean of its divisors is an integer number (110861985).

Almost surely, 2^221723969 is an apocalyptic number.

It is an amenable number.

221723969 is a deficient number, since it is larger than the sum of its proper divisors (1).

221723969 is an equidigital number, since it uses as much as digits as its factorization.

221723969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 81648, while the sum is 41.

The square root of 221723969 is about 14890.3985507440. The cubic root of 221723969 is about 605.2538324263.

The spelling of 221723969 in words is "two hundred twenty-one million, seven hundred twenty-three thousand, nine hundred sixty-nine".