221997011 has 2 divisors, whose sum is σ = 221997012. Its totient is φ = 221997010.

The previous prime is 221996993. The next prime is 221997079. The reversal of 221997011 is 110799122.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221997011 - 2²⁶ = 154888147 is a prime.

It is not a weakly prime, because it can be changed into another prime (221997211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110998505 + 110998506.

It is an arithmetic number, because the mean of its divisors is an integer number (110998506).

Almost surely, 2^221997011 is an apocalyptic number.

221997011 is a deficient number, since it is larger than the sum of its proper divisors (1).

221997011 is an equidigital number, since it uses as much as digits as its factorization.

221997011 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2268, while the sum is 32.

The square root of 221997011 is about 14899.5641211413. The cubic root of 221997011 is about 605.5021771402.

The spelling of 221997011 in words is "two hundred twenty-one million, nine hundred ninety-seven thousand, eleven".